Organic compound, anthracene derivative, and light-emitting element, light-emitting device, and electronic device using anthracene derivative

ABSTRACT

Objects of the present invention are to provide novel anthracene derivatives and novel organic compounds; a light-emitting element that has high emission efficiency; a light-emitting element that is capable of emitting blue light with high luminous efficiency; a light-emitting element that is capable of operation for a long time; and a light-emitting device and an electronic device that have lower power consumption. An anthracene derivative represented by a general formula (1) and an organic compound represented by a general formula (17) are provided. A light-emitting element that has high emission efficiency can be obtained by use of the anthracene derivative represented by the general formula (1). Further, a light-emitting element that has a long life can be obtained by use of the anthracene derivative represented by the general formula (1).

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to organic compounds, anthracenederivatives, and light-emitting elements, light-emitting devices, andelectronic devices each of which use the anthracene derivatives.

2. Description of the Related Art

Light-emitting elements that use light-emitting materials haveadvantages of being thin, being lightweight, and the like, and areexpected to be applied to next-generation displays. Further, since thelight-emitting elements are self-light-emitting elements, thelight-emitting elements are superior to liquid crystal displays (LCDs)because they have high visibility without a problem such as a viewingangle.

A basic structure of a light-emitting element is a structure in which alight-emitting layer is included between a pair of electrodes. It issaid that, when a voltage is applied to such a light-emitting element,holes injected from an anode and electrons injected from a cathode arerecombined with each other in a luminescent center of the light-emittinglayer to excite molecules, and the molecular excitons release energy inreturning to a ground state, whereby light is emitted. It is to be notedthat excited states generated by the recombination include a singletstate and a triplet state. The light emission can be obtained in eitherof the excited states. In particular, the light emission occurring whenthe singlet-excited state directly returns to the ground state isreferred to as fluorescence, and the light emission occurring when thetriplet-excited state returns to the ground state is referred to asphosphorescence.

With such light-emitting elements, there are a lot of material-relatedproblems for improvement of element characteristics. In order to solvethe problems, improvement of an element structure, development ofmaterials, and the like have been carried out.

For example, in Patent Document 1: United States Patent ApplicationPublication No. 2005-0260442, an anthracene derivative that emits greenlight is described. However, Patent Document 1 discloses only theemission spectrum of the anthracene derivative but not the deviceperformance for when the anthracene derivative was applied to alight-emitting element.

Also, in Patent Document 2: Japanese Published Patent Application No.2004-91334, a light-emitting element in which an anthracene derivativeis used for a charge transporting layer is described. However, in PatentDocument 2, there is no description of the life of the light-emittingelement.

If commercialization is considered, extending the life of thelight-emitting element is an important issue. Further, the developmentof light-emitting elements with much higher levels of performance isdesired.

SUMMARY OF THE INVENTION

In view of the foregoing problems, objects of the present invention areto provide novel organic compounds and anthracene derivatives.

Another object of the present invention is to provide a light-emittingelement that has emission efficiency. Further, another object of thepresent invention is to provide a light-emitting element that emits bluelight at high luminous efficiency. Another object of the presentinvention is to provide a light-emitting device that is capable ofoperation for a long time.

Another object of the present invention is to provide a light-emittingdevice and electronic device that have reduced power consumption.

As a result of diligent study, the inventors have found that theproblems can be solved with an anthracene derivative represented by ageneral formula (1) given below.

Thus, one aspect of the present invention is an anthracene derivativerepresented by the general formula (1) given below.

In the general formula (1), Ar represents an aryl group having 6 to 25carbon atoms; α represents an arylene group having 6 to 25 carbon atoms;A is represented by any of the above structural formulae (2-1) to (2-3);β¹ to β³ each represent a substituted or unsubstituted benzene ring; andB is any of hydrogen, an alkyl group having 1 to 4 carbon atoms, an arylgroup having 6 to 25 carbon atoms, a halogen group, and a haloalkylgroup or is represented by any of the above structural formulae (2-1) to(2-3).

A more preferable aspect of the present invention is an anthracenederivative represented by the above general formula (1) in which β¹ isan unsubstituted benzene ring.

One aspect of the present invention is an anthracene derivativerepresented by a general formula (3) given below.

In the general formula (3), Ar represents an aryl group having 6 to 25carbon atoms; α represents an arylene group having 6 to 25 carbon atoms;R¹ to R⁶ each represent any of hydrogen, an alkyl group having 1 to 4carbon atoms, a halogen group, a haloalkyl group, and an aryl grouphaving 6 to 25 carbon atoms and may be the same or different from oneanother; and B represents any of hydrogen, an alkyl group having 1 to 4carbon atoms, an aryl group having 6 to 25 carbon atoms, a halogengroup, and a haloalkyl group or is represented by the above structuralformula (4). In the structural formula (4), R¹ to R⁶ each represent anyof hydrogen, an alkyl group having 1 to 4 carbon atoms, a halogen group,a haloalkyl group, and an aryl group having 6 to 25 carbon atoms and maybe the same or different from one another.

One aspect of the present invention is an anthracene derivativerepresented by a general formula (5) given below.

In the general formula (5), Ar represents an aryl group having 6 to 25carbon atoms; α represents an arylene group having 6 to 25 carbon atoms;and B represents any of hydrogen, an alkyl group having 1 to 4 carbonatoms, an aryl group having 6 to 25 carbon atoms, a halogen group, and ahaloalkyl group or is represented by the above structural formula (6).

One aspect of the present invention is an anthracene derivativerepresented by a general formula (7) given below.

In the general formula (7), Ar represents an aryl group having 6 to 25carbon atoms; α represents an arylene group having 6 to 25 carbon atoms;R⁷ and R⁸ each represent any of hydrogen, an alkyl group having 1 to 4carbon atoms, a halogen group, a haloalkyl group, and an aryl grouphaving 6 to 25 carbon atoms and may be the same or different from oneanother; B represents any of hydrogen, an alkyl group having 1 to 4carbon atoms, an aryl group having 6 to 25 carbon atoms, a halogengroup, and a haloalkyl group or is represented by the above structuralformula (8); and, in the above structural formula (8), R⁷ and R⁸ eachrepresent any of hydrogen, an alkyl group having 1 to 4 carbon atoms, ahalogen group, a haloalkyl group, and an aryl group having 6 to 25carbon atoms and may be the same or different from one another.

One aspect of the present invention is an anthracene derivativerepresented by a general formula (9) given below.

In the general formula (9), Ar represents an aryl group having 6 to 25carbon atoms; α represents an arylene group having 6 to 25 carbon atoms;R⁹ and R¹⁰ each represent any of hydrogen, an alkyl group having 1 to 4carbon atoms, a halogen group, a haloalkyl group, and an aryl grouphaving 6 to 25 carbon atoms and may be the same or different from oneanother; B represents any of hydrogen, an alkyl group having 1 to 4carbon atoms, an arylene group having 6 to 25 carbon atoms, a halogengroup, and a haloalkyl group or is represented by the above structuralformula (10); and, in the above structural formula (10), R⁹ and R¹⁰ eachrepresent any of hydrogen, an alkyl group having 1 to 4 carbon atoms, ahalogen group, a haloalkyl group, and an aryl group having 6 to 25carbon atoms and may be the same or different from one another.

One aspect of the present invention is an anthracene derivativerepresented by a general formula (11) given below.

In the general formula (11), Ar represents an aryl group having 6 to 25carbon atoms; α represents an arylene group having 6 to 25 carbon atoms;and B represents any of hydrogen, an alkyl group having 1 to 4 carbonatoms, an aryl group having 6 to 25 carbon atoms, a halogen group, and ahaloalkyl group or is represented by the above structural formula (12).

One aspect of the present invention is an anthracene derivativerepresented by a general formula (13) given below.

In the general formula (13), Ar represents an aryl group having 6 to 25carbon atoms; α represents an arylene group having 6 to 25 carbon atoms;R³⁰ to R³⁹ each represent any of hydrogen, an alkyl group having 1 to 4carbon atoms, a halogen group, a haloalkyl group, and an aryl grouphaving 6 to 25 carbon atoms and may be the same or different from oneanother; and B represents any of hydrogen, an alkyl group having 1 to 4carbon atoms, an aryl group having 6 to 25 carbon atoms, a halogengroup, and a haloalkyl group or is represented by the above structuralformula (14). In the structural formula (14), R³⁰ to R³⁹ each representany of hydrogen, an alkyl group having 1 to 4 carbon atoms, a halogengroup, a haloalkyl group, and an aryl group having 6 to 25 carbon atomsand may be the same or different from one another.

One aspect of the present invention is an anthracene derivativerepresented by a general formula (15) given below.

In the general formula (15), Ar represents an aryl group having 6 to 25carbon atoms; α represents an arylene group having 6 to 25 carbon atoms;and B represents any of hydrogen, an alkyl group having 1 to 4 carbonatoms, an aryl group having 6 to 25 carbon atoms, a halogen group, and ahaloalkyl group or is represented by the above structural formula (16).

One aspect of the present invention is a light-emitting elementincluding any of the above anthracene derivatives.

The light-emitting element of the present invention thus obtained can bemade to have a long life, and therefore, a light-emitting device (e.g.,an image display device) using such light-emitting element can be madeto have a long life. Thus, the present invention also covers thelight-emitting device and an electronic device each of which uses thelight-emitting element of the present invention.

The light-emitting device of the present invention includes alight-emitting element including any of the above-described anthracenederivatives, and a control circuit configured to control light emissionfrom the light-emitting element. The light-emitting device in thisspecification includes an image display device that uses alight-emitting element. Further, the category of the light-emittingdevice also includes a module in which a tape automated bonding (TAB)tape or a tape carrier package (TCP) is attached to a light-emittingelement; a module in which a printed wiring board is provided at an endof a TAB tape or a TCP; and a module in which an integrated circuit (IC)is directly mounted on a light-emitting element by a chip on glass (COG)method. Moreover, a light-emitting device used in a lighting device orthe like is also included.

Further, an electronic device that uses the light-emitting element ofthe present invention in its display portion is also included in thecategory of the present invention. Accordingly, one aspect of thepresent invention is an electronic device having a display portion,where the display portion includes the above-described light-emittingelement and a control circuit configured to control light emission fromthe light-emitting element.

Furthermore, the present invention covers also organic compounds usedfor synthesis of the anthracene derivatives of the present inventionbecause the organic compounds used for synthesis of the anthracenederivatives of the present invention are novel materials. Accordingly,one aspect of the present invention is an organic compound representedby a general formula (17) given below.

In the general formula (17), R¹ to R⁶ each represent any of hydrogen, analkyl group having 1 to 4 carbon atoms, a halogen group, a haloalkylgroup, and an aryl group having 6 to 25 carbon atoms and may be the sameor different from one another; and B represents any of hydrogen, analkyl group having 1 to 4 carbon atoms, an aryl group having 6 to 25carbon atoms, a halogen group, and a haloalkyl group or is representedby the above structural formula (18). In the structural formula (18), R¹to R⁶ each represent any of hydrogen, an alkyl group having 1 to 4carbon atoms, an aryl group having 6 to 25 carbon atoms, a halogengroup, and a haloalkyl group, and may be the same or different from oneanother.

One aspect of the present invention is an organic compound representedby a general formula (19) given below.

In the general formula (19), B represents any of hydrogen, an alkylgroup having 1 to 4 carbon atoms, an aryl group having 6 to 25 carbonatoms, a halogen group, and a haloalkyl group or is represented by theabove structural formula (20).

One aspect of the present invention is an organic compound representedby a general formula (21) given below.

In the general formula (21), R⁷ and R⁸ each represent any of hydrogen,an alkyl group having 1 to 4 carbon atoms, a halogen group, a haloalkylgroup, and an aryl group having 6 to 25 carbon atoms and may be the sameor different from one another; B represents any of hydrogen, an alkylgroup having 1 to 4 carbon atoms, an aryl group having 6 to 25 carbonatoms, a halogen group, and a haloalkyl group or is represented by theabove structural formula (22); and, in the above structural formula(22), R⁷ and R⁸ each represent any of hydrogen, an alkyl group having 1to 4 carbon atoms, a halogen group, a haloalkyl group, and an aryl grouphaving 6 to 25 carbon atoms and may be the same or different from oneanother.

One aspect of the present invention is an organic compound representedby a general formula (23) given below.

In the general formula (23), R⁹ and R¹⁰ each represent any of hydrogen,an alkyl group having 1 to 4 carbon atoms, a halogen group, a haloalkylgroup, and an aryl group having 6 to 25 carbon atoms and may be the sameor different from one another; B represents any of hydrogen, an alkylgroup having 1 to 4 carbon atoms, an aryl group having 6 to 25 carbonatoms, a halogen group, and a haloalkyl group or is represented by theabove structural formula (24); and, in the above structural formula(24), R⁹ and R¹⁰ each represent any of hydrogen, an alkyl group having 1to 4 carbon atoms, a halogen group, a haloalkyl group, and an aryl grouphaving 6 to 25 carbon atoms and may be the same or different from oneanother.

One aspect of the present invention is an organic compound representedby a general formula (25) given below.

In the general formula. (25), B represents any of hydrogen, an alkylgroup having 1 to 4 carbon atoms, an aryl group having 6 to 25 carbonatoms, a halogen group, and a haloalkyl group or is represented by theabove structural formula (26).

One aspect of the present invention is an organic compound representedby a general formula (27) given below.

In the general formula (27), R³⁰ to R³⁹ each represent any of hydrogen,an alkyl group having 1 to 4 carbon atoms, a halogen group, a haloalkylgroup, and an aryl group having 6 to 25 carbon atoms and may be the sameor different from one another; and B represents any of hydrogen, analkyl group having 1 to 4 carbon atoms, an aryl group having 6 to 25carbon atoms, a halogen group, and a haloalkyl group or is representedby the above structural formula (28). In the structural formula (28),R³⁰ to R³⁹ each represent any of hydrogen, an alkyl group having 1 to 4carbon atoms, a halogen group, a haloalkyl group, and an aryl grouphaving 6 to 25 carbon atoms and may be the same or different from oneanother.

One aspect of the present invention is an organic compound representedby a general formula (29) given below.

In the general formula (29), B represents any of hydrogen, an alkylgroup having 1 to 4 carbon atoms, an aryl group having 6 to 25 carbonatoms, a halogen group, and a haloalkyl group or is represented by theabove structural formula (30).

The anthracene derivatives of the present invention emit light at highefficiency. Therefore, by use of any of the anthracene derivatives ofthe present invention in a light-emitting element, a light-emittingelement with high emission efficiency can be obtained. Also, by use ofany of the anthracene derivatives of the present invention in alight-emitting element, the light-emitting element with a long life canbe obtained.

Further, by use of any of the anthracene derivatives of the presentinvention, a light-emitting device and electronic device each having along life can be obtained.

BRIEF DESCRIPTION OF THE DRAWINGS

In the accompanying drawings:

FIG. 1 illustrates a light-emitting element of the present invention;

FIG. 2 illustrates a light-emitting element of the present invention;

FIG. 3 illustrates a light-emitting element of the present invention;

FIGS. 4A and 4B illustrate a light-emitting device of the presentinvention;

FIGS. 5A and 5B illustrate a light-emitting device of the presentinvention;

FIGS. 6A to 6D illustrate electronic devices of the present invention;

FIG. 7 illustrates a lighting device of the present invention;

FIG. 8 illustrates a lighting device of the present invention;

FIG. 9 illustrates a lighting device of the present invention;

FIG. 10 is a ¹H-NMR chart of PCC;

FIG. 11 is a ¹H-NMR chart of PCCPA;

FIG. 12 illustrates an absorption spectrum and an emission spectrum of atoluene solution of PCCPA;

FIG. 13 illustrates an absorption spectrum and an emission spectrum of athin film of PCCPA;

FIG. 14 illustrates a cyclic voltammogram (oxidation) of PCCPA;

FIG. 15 illustrates a cyclic voltammogram (reduction) of PCCPA;

FIG. 16 is a ¹H-NMR chart of TPC;

FIG. 17 is a ¹H-NMR chart of TPCPA;

FIG. 18 illustrates an absorption spectrum and an emission spectrum of atoluene solution of TPCPA;

FIG. 19 illustrates an absorption spectrum and an emission spectrum of athin film of TPCPA;

FIG. 20 illustrates a cyclic voltammogram (oxidation) of TPCPA;

FIG. 21 illustrates a cyclic voltammogram (reduction) of TPCPA;

FIG. 22 illustrates a light-emitting element of Example 2;

FIG. 23 illustrates current density-luminance characteristics of alight-emitting element manufactured in Example 2;

FIG. 24 illustrates voltage-luminance characteristics of alight-emitting element manufactured in Example 2;

FIG. 25 illustrates luminance-current efficiency characteristics of alight-emitting element manufactured in Example 2;

FIG. 26 illustrates an emission spectrum of a light-emitting elementmanufactured in Example 2;

FIG. 27 illustrates current density-luminance characteristics of alight-emitting element manufactured in Example 2;

FIG. 28 illustrates voltage-luminance characteristics of alight-emitting element manufactured in Example 2;

FIG. 29 illustrates luminance-current efficiency characteristics of alight-emitting element manufactured in Example 2;

FIG. 30 illustrates an emission spectrum of a light-emitting elementmanufactured in Example 2;

FIG. 31 illustrates current density-luminance characteristics of alight-emitting element manufactured in Comparative Example 1;

FIG. 32 illustrates voltage-luminance characteristics of alight-emitting element manufactured in Comparative Example 1;

FIG. 33 illustrates luminance-current efficiency characteristics of alight-emitting element manufactured in Comparative Example 1;

FIG. 34 illustrates an emission spectrum of a light-emitting elementmanufactured in Comparative Example 1;

FIG. 35 illustrates a measurement result of reliability oflight-emitting elements manufactured in Example 2.

FIG. 36 illustrates current density-luminance characteristics of alight-emitting element manufactured in Example 3;

FIG. 37 illustrates voltage-luminance characteristics of alight-emitting element manufactured in Example 3;

FIG. 38 illustrates luminance-current efficiency characteristics of alight-emitting element manufactured in Example 3;

FIG. 39 illustrates an emission spectrum of a light-emitting elementmanufactured in Example 3;

FIG. 40 illustrates current density-luminance characteristics of alight-emitting element manufactured in Example 3;

FIG. 41 illustrates voltage-luminance characteristics of alight-emitting element manufactured in Example 3;

FIG. 42 illustrates luminance-current efficiency characteristics of alight-emitting element manufactured in Example 3;

FIG. 43 illustrates an emission spectrum of a light-emitting elementmanufactured in Example 3;

FIG. 44 illustrates current density-luminance characteristics of alight-emitting element manufactured in Comparative Example 2;

FIG. 45 illustrates voltage-luminance characteristics of alight-emitting element manufactured in Comparative Example 2;

FIG. 46 illustrates luminance-current efficiency characteristics of alight-emitting element manufactured in Comparative Example 2;

FIG. 47 illustrates an emission spectrum of a light-emitting elementmanufactured in Comparative Example 2;

FIGS. 48A and 48B are ¹H-NMR charts of PC2C;

FIGS. 49A and 49B are ¹H-NMR charts of PC2CPA;

FIG. 50 illustrates an absorption spectrum of a toluene solution ofPC2CPA;

FIG. 51 illustrates an emission spectrum of a toluene solution ofPC2CPA;

FIG. 52 illustrates an absorption spectrum of a thin film of PC2CPA;

FIG. 53 illustrates an emission spectrum of a thin film of PC2CPA;

FIGS. 54A and 54B are ¹H-NMR charts of TP2C;

FIGS. 55A and 55B are ¹H-NMR charts of TP2CPA;

FIG. 56 illustrates an absorption spectrum of a toluene solution ofTP2CPA;

FIG. 57 illustrates an emission spectrum of a toluene solution ofTP2CPA;

FIG. 58 illustrates an absorption spectrum of a thin film of TP2CPA;

FIG. 59 illustrates an emission spectrum of a thin film of TP2CPA;

FIGS. 60A and 60B are ¹H-NMR charts of CPC;

FIGS. 61A and 61B are ¹H-NMR charts of CPCPA;

FIG. 62 illustrates an absorption spectrum of a toluene solution ofCPCPA;

FIG. 63 illustrates an emission spectrum of a toluene solution of CPCPA;

FIG. 64 illustrates an absorption spectrum of a thin film of CPCPA;

FIG. 65 illustrates an emission spectrum of a thin film of CPCPA;

FIGS. 66A and 66B are ¹H-NMR charts of CP2C;

FIGS. 67A and 67B are ¹H-NMR charts of CP2CPA;

FIG. 68 illustrates an absorption spectrum of a toluene solution ofCP2CPA;

FIG. 69 illustrates an emission spectrum of a toluene solution ofCP2CPA;

FIG. 70 illustrates an absorption spectrum of a thin film of CP2CPA; and

FIG. 71 illustrates an emission spectrum of a thin film of CP2CPA.

DETAILED DESCRIPTION OF THE INVENTION

Hereinafter, embodiment modes and examples of the present invention aredescribed using the accompanying drawings. It is to be noted that thepresent invention can be carried out in many a variety of modes. It iseasily understood by those skilled in the art that a variety of changesmay be made in forms and details without departing from the spirit andthe scope of the present invention. Therefore, the present inventionshould not be limited to the description of the embodiment modes andexamples below.

Embodiment Mode 1

In this embodiment mode, anthracene derivatives of the present inventionare described.

An anthracene derivative of the present invention is represented by ageneral formula (31).

In the above general formula (31), Ar represents an aryl group having 6to 25 carbon atoms; α represents an arylene group having 6 to 25 carbonatoms; A is represented by any of the above structural formulae (32-1)to (32-3); β¹ to β³ each represent a substituted or unsubstitutedbenzene ring; and B is any of hydrogen, an alkyl group having 1 to 4carbon atoms, an aryl group having 6 to 25 carbon atoms, a halogengroup, and a haloalkyl group or is represented by any of the abovestructural formulae (32-1) to (32-3).

In the general formula (31), as examples of the substituent representedby Ar, substituents represented by structural formulae (33-1) to (33-9)are given.

In the general formula (31), as examples of the substituent representedby α, substituents represented by structural formulae (34-1) to (34-9)are given.

In the above general formula (31), Ar and a each may be substituted witheither an alkyl group having 1 to 4 carbon atoms or an alkoxy grouphaving 1 to 4 carbon atoms. The solubility of the anthracene derivativeof the present invention is increased, whereby a light-emitting elementcan be fabricated by a wet process. Examples of the above alkyl grouphaving 1 to 4 carbon atoms include a methyl group, an ethyl group, and abutyl group. Examples of the above alkoxy group having 1 to 4 carbonatoms include a methoxy group, an ethoxy group, and a butoxy group.

Examples of the anthracene derivatives of the present invention include,but are not limited to, anthracene derivatives represented by structuralformulae (101) to (414) given below.

The anthracene derivatives of the present invention can be synthesizedby any of a variety of methods. For example, the synthesis can beperformed by the use of any of the synthesis methods shown in synthesisschemes (a-1) to (a-3) given below.

First, 9-halid-10-arylanthracene (compound 1) and boronic acid which isan aryl halide or an organic boron compound which is an aryl halide(compound 7) are coupled by Suzuki-Miyaura Coupling using a palladiumcatalyst, and thus 9-(aryl halide)-10-arylanthracene (compound 2) can beobtained. In the reaction formula, X¹ represents halogen or a triflategroup, and X² represents halogen. When X¹ is halogen, X¹ and X² may bethe same or different from one another. Use of iodine and bromine arepreferable for the halogen. It is more preferable that X¹ be iodine andX² be bromine. Further, R¹⁰⁰ and R¹⁰¹ each represent hydrogen or analkyl group having 1 to 6 carbon atoms, may be the same or differentfrom one another, and may be combined with each other to form a ring. Arrepresents an aryl group having 6 to 25 carbon atoms. In addition, arepresents an arylene group having 6 to 25 carbon atoms. Examples of thepalladium catalyst that can be used in the synthesis scheme (a-1)include, but are not limited to, palladium(II) acetate andtetrakis(triphenylphosphine)palladium(0). Examples of a ligand in thepalladium catalyst, which can be used in the synthesis scheme (a-1),include, but are not limited to, tri(ortho-tolyl)phosphine,triphenylphosphine, and tricyclohexylphosphine. Examples of a base thatcan be used in the synthesis scheme (a-1) include, but are not limitedto, an organic base such as sodium tert-butoxide and an inorganic basesuch as potassium carbonate. Examples of a solvent that can be used inthe synthesis scheme (a-1) include, but are not limited to, a mixedsolvent of toluene and water; a mixed solvent of toluene, an alcoholsuch as ethanol, and water; a mixed solvent of xylene and water; a mixedsolvent of xylene, an alcohol such as ethanol, and water; a mixedsolvent of benzene and water; a mixed solvent of benzene, an alcoholsuch as ethanol, and water; and a mixed solvent of ether such asethyleneglycoldimethylether and water. Use of a mixed solvent of tolueneand water or a mixed solvent of toluene, ethanol, and water is morepreferable.

3-carbazole halide (compound 3) and boronic acid which is a triarylamineor an organic boron compound which is a triarylamine (compound 4) arecoupled by Suzuki-Miyaura Coupling using a palladium catalyst, and thusa carbazole compound in which the 3-position is substituted withtriarylamine (compound 5) can be obtained. In the formula, X⁴ representsa halogen or a triflate group, and iodine or bromine can be used as thehalogen. Further, R¹⁰² and R¹⁰³ each represent hydrogen or an alkylgroup having 1 to 6 carbon atoms, may be the same or different from oneanother, and combined with each other to form a ring. β¹ to β³ eachrepresent a substituted or unsubstituted benzene ring. Examples of thepalladium catalyst that can be used in the synthesis scheme (a-2)include, but are not limited to, palladium(II) acetate andtetrakis(triphenylphosphine)palladium(0). Examples of a ligand of thepalladium catalyst, which can be used in the synthesis scheme (a-2),include, but are not limited to, tri(ortho-tolyl)phosphine,triphenylphosphine, and tricyclohexylphosphine. Examples of a base thatcan be used in the synthesis scheme (a-2) include, but are not limitedto, an organic base such as sodium tert-butoxide and an inorganic basesuch as potassium carbonate. Examples of a solvent that can be used inthe synthesis scheme (a-2) include, but are not limited to, a mixedsolvent of toluene and water; a mixed solvent of toluene, an alcoholsuch as ethanol, and water; a mixed solvent of xylene and water; a mixedsolvent of xylene, an alcohol such as ethanol, and water; a mixedsolvent of benzene and water; a mixed solvent of benzene, an alcoholsuch as ethanol, and water; and a mixed solvent of ether such asethyleneglycoldimethylether and water. Use of a mixed solvent of tolueneand water or a mixed solvent of toluene, ethanol and water is morepreferable.

Then, 9-(aryl halide)-10-arylanthracene (compound 2), which is obtainedby the synthesis scheme (a-1), and a carbazole (compound 5) compound inwhich the 3-position is substituted with triarylamine are coupled by aBuchwald-Hartwig reaction using a palladium catalyst or an Ullmannreaction using copper or a copper compound; thus, compound 6 which isone of the anthracene derivatives of the present invention can beobtained. In the case where a Buchwald-Hartwig reaction is performed ina synthesis scheme (a-3), examples of the palladium catalyst that can beused in the synthesis scheme (a-3) include, but are not limited to,bis(dibenzylideneacetone)palladium(0) and palladium(II) acetate.Examples of a ligand in the palladium catalyst, which can be used in thesynthesis scheme (a-3), include, but are not limited to,tri(tert-butyl)phosphine, tri(n-hexyl)phosphine, andtricyclohexylphosphine. Examples of a base that can be used in thesynthesis scheme (a-3) include, but are not limited to, an organic basesuch as sodium tert-butoxide and an inorganic base such as potassiumcarbonate. Examples of a solvent that can be used in the synthesisscheme (a-3) include, but are not limited to, toluene, xylene, benzene,tetrahydrofuran. The case in which an Ullmann reaction is performed in asynthesis scheme (a-3) is described. In the synthesis scheme (a-3), R¹⁰⁴and R¹⁰⁵ each represent a halogen, an acetyl group, or the like, andchlorine, bromine, or iodine can be used as the halogen. It is preferredthat R¹⁰⁴ be iodine to form copper(I) iodide or that R¹⁰⁵ be an acetylgroup to form a copper(II) acetate. The copper compound used for thereaction is not limited to these, and copper can be used instead of thecopper compound. Examples of a base that can be used in the synthesisscheme (a-3) include, but are not limited to, an inorganic base such aspotassium carbonate. Examples of a solvent that can be used in thesynthesis scheme (a-3) include, but are not limited to,1,3-dimethyl-3,4,5,6-tetrahydro-2(1H)pyrimidinone (DMPU), toluene,xylene, and benzene. Use of DMPU or xylene which has a high boilingpoint is preferable because, by an Ullmann reaction, an object can beobtained in a shorter time and at a higher yield when the reactiontemperature is greater than or equal to 100° C. Since it is furtherpreferable that the reaction temperature be a temperature greater thanor equal to 150° C., DMPU is more preferably used. In the formula, Arrepresents an aryl group having 6 to 25 carbon atoms; α represents anarylene group having 6 to 25 carbon atoms; X² represents a halogen; andβ¹ to β³ each represent a substituted or unsubstituted benzene ring. Itis to be noted that the “compound 6” is a compound formed underconditions in which, in the above-described general formula (31), A isrepresented by a general formula (32-1) and B is hydrogen.

Each of the anthracene derivatives of the present invention have a highquantum yield, and emit blue to blue green light. Therefore, each of theanthracene derivatives of the present invention is suitable for use in alight-emitting element. Also, since the anthracene derivatives of thepresent invention are stable with respect to repetitive redox reactions,a light-emitting element that use any of the anthracene derivatives ofthe present invention can be made to have a long life.

Embodiment Mode 2

In this embodiment mode, organic compounds that are materials used forthe synthesis of the anthracene derivatives of the present invention aredescribed. These organic compounds are novel materials and are thusincluded as one aspect of the present invention.

The above organic compounds are any of the organic compounds representedby general formulae (149-1), (150-1), and (151-1).

In the above general formula (149-1), R¹ to R⁶ each represent any ofhydrogen, an alkyl group having 1 to 4 carbon atoms, a halogen group, ahaloalkyl group, and an aryl group having 6 to 25 carbon atoms and maybe the same or different from one another; and B represents any ofhydrogen, an alkyl group having 1 to 4 carbon atoms, an aryl grouphaving 6 to 25 carbon atoms, a halogen group, and a halo alkyl group oris represented by the above structural formula (149-2). In thestructural formula (149-2), R¹ to R⁶ each represent any of hydrogen, analkyl group having 1 to 4 carbon atoms, a halogen group, a haloalkylgroup, and an aryl group having 6 to 25 carbon atoms and may be the sameor different from one another.

In the general formula (150-1), R⁷ and R⁸ each represent any ofhydrogen, an alkyl group having 1 to 4 carbon atoms, a halogen group, ahaloalkyl group, and an aryl group having 6 to 25 carbon atoms and maybe the same or different from one another; and B represents any ofhydrogen, an alkyl group having 1 to 4 carbon atoms, an aryl grouphaving 6 to 25 carbon atoms, a halogen group, and a haloalkyl group oris represented by the above structural formula (150-2). In the abovestructural formula (150-2), R⁷ and R⁸ each represent any of hydrogen, analkyl group having 1 to 4 carbon atoms, a halogen group, a haloalkylgroup, and an aryl group having 6 to 25 carbon atoms and may be the sameor different from one another.

In the general formula (151-1), R³⁰ to R³⁹ each represent any ofhydrogen, an alkyl group having 1 to 4 carbon atoms, a halogen group, ahaloalkyl group, and an aryl group having 6 to 25 carbon atoms and maybe the same or different from one another; and B represents any ofhydrogen, an alkyl group having 1 to 4 carbon atoms, an aryl grouphaving 6 to 25 carbon atoms, a halogen group, and a haloalkyl group oris represented by the above structural formula (151-2). In thestructural formula (151-2), R³⁰ to R³⁹ each represent any of hydrogen,an alkyl group having 1 to 4 carbon atoms, a halogen group, a haloalkylgroup, and an aryl group having 6 to 25 carbon atoms and may be the sameor different from one another.

Specific examples of the above organic compounds include organiccompounds represented by structural formulae (501) to (802). However, itis to be noted that the present invention is not limited to these.

The above organic compounds can be synthesized by any of a variety ofmethods. For example, the synthesis can be performed by a similarsynthesis method to the one of the compound 5, which is described inEmbodiment Mode 1 (the synthesis scheme (a-2)).

Embodiment Mode 3

Hereinafter, one mode of a light-emitting element that uses any of theanthracene derivatives of the present invention is described using FIG.1.

The light-emitting element of the present invention includes a pluralityof layers between a pair of electrodes. For the plurality of layers, acombination of layers each including a substance having a highcarrier-injecting property or a substance having a highcarrier-transporting property is stacked so that a light-emitting regionis formed apart from the electrodes, in other words, carriers arerecombined in a portion apart from the electrodes.

In this embodiment mode, the light-emitting element includes a firstelectrode 101, a second electrode 103, and a layer 102 including anorganic compound formed between the first electrode 101 and the secondelectrode 103 is described. In addition, in this embodiment mode, it isassumed that the first electrode 101 serves as an anode and the secondelectrode 103 serves as a cathode. In other words, in the descriptionbelow, it is assumed that light emission can be obtained when a voltageis applied to the first electrode 101 and the second electrode 103 sothat the potential of the first electrode 101 is higher than that of thesecond electrode 103.

A substrate 100 is used as a support of the light-emitting element. Forthe substrate 100, glass, plastic, or the like can be used, for example.It is to be noted that materials other than glass and plastic can beused as long as they can function as a support in a manufacturingprocess of a light-emitting element.

It is preferred that the first electrode 101 be formed using any ofmetal, alloy, and an electrically conductive compound each having a highwork function (4.0 eV or higher), a mixture thereof, or the like.Specifically, indium tin oxide (ITO), indium tin oxide containingsilicon or silicon oxide, indium zinc oxide (IZO), indium oxidecontaining tungsten oxide and zinc oxide (IWZO), or the like can beused. Films of such electrically conductive metal oxide are typicallyformed by sputtering, but may also be formed by applying a sol-gelmethod or the like. For example, indium zinc oxide (IZO) can be formedby a sputtering method using a target in which 1 to 20 wt % of zincoxide is added to indium oxide. Indium oxide containing tungsten oxideand zinc oxide (IWZO) can be formed by a sputtering method using atarget in which 0.5 to 5 wt % of tungsten oxide and 0.1 to 1 wt % ofzinc oxide are added to indium oxide. Further, gold (Au), platinum (Pt),nickel (Ni), tungsten (W), chromium (Cr), molybdenum (Mo), iron (Fe),cobalt (Co), copper (Cu), palladium (Pd), nitride of a metal material(e.g., titanium nitride), or the like can be used as the material forthe first electrode 101.

There is no particular limitation on a stacked structure of a layer 102including an organic compound. It is acceptable as long as the layer 102including an organic compound is formed by any combination of alight-emitting layer described in this embodiment mode, with layers eachincluding a substance having a high electron-transporting property, asubstance having a high electron-injecting property, a substance havinga high hole-injecting property, a substance having a highhole-transporting property, a bipolar substance (a substance having highelectron-transporting and a hole-transporting property), or the like.For example, any combination of a hole-injecting layer, ahole-transporting layer, a hole-blocking layer, a light-emitting layer,an electron-transporting layer, an electron-injecting layer, and thelike can be employed. This embodiment mode describes a structure of theEL layer 103, in which a hole-injecting layer 111, a hole-transportinglayer 112, a light-emitting layer 113, and an electron-transportinglayer 114 are sequentially stacked over the first electrode 101.

The hole-injecting layer 111 is a layer that includes a substance havinga high hole-injecting property. As a substance having a highhole-injecting property, molybdenum oxide, vanadium oxide, rutheniumoxide, tungsten oxide, manganese oxide, or the like can be used.Alternatively, the hole-injecting layer 111 can be formed using any oneof the following materials: phthalocyanine based compounds such asphthalocyanine (H₂PC) and copper phthalocyanine (CuPc); aromatic aminecompounds such as4,4′-bis[N-(4-diphenylaminophenyl)-N-phenylamino]biphenyl (DPAB) and4,4′-bis(N-{4-[N-(3-methylphenyl)-N-phenylamino]phenyl}-N-phenylamino)biphenyl(DNTPD); high molecular compounds such aspoly(ethylenedioxythiophene)/poly(styrenesulfonic acid) (PEDOTTPSS); andthe like.

Alternatively, the hole-injecting layer 111 can be formed using acomposite material in which an acceptor substance is mixed into asubstance having a high hole-transporting property. It is to be notedthat a material for forming the electrode can be selected regardless ofits work function by use of the composite material in which an acceptorsubstance is mixed into a substance having a high hole-transportingproperty. That is, not only a high-work function material, but also alow-work function material can be used for the first electrode 101.Examples of the acceptor substance include7,7,8,8-tetracyano-2,3,5,6-tetrafluoroquinodimethane (F₄-TCNQ);chloranil; transition metal oxide; and oxide of metals that belong toGroup 4 to Group 8 of the periodic table. Specifically, any of vanadiumoxide, niobium oxide, tantalum oxide, chromium oxide, molybdenum oxide,tungsten oxide, manganese oxide, and rhenium oxide is preferably usedbecause of their high electron accepting properties. In particular, useof molybdenum oxide is more preferable because of its stability in theatmosphere, a low hygroscopic property, and easiness of handling.

As the organic compound used for the composite material, any of avariety of compounds such as an aromatic amine compound, a carbazolederivative, aromatic hydrocarbon, and a high molecular compound (such asan oligomer, a dendrimer, or a polymer) can be used. It is preferablethat the organic compound used for the composite material have a highhole-transporting property. Specifically, a substance having a holemobility of greater than or equal to 10⁻⁶ cm²/Vs is preferably used. Itis to be noted that any substance other than the above substances mayalso be used as long as it is a substance in which the hole-transportingproperty is higher than the electron-transporting property. The organiccompounds that can be used for the composite material are specificallyshown below.

Examples of the aromatic amine compound includeN,N′-di(p-tolyl)-N,N′-diphenyl-p-phenylenediamine (DTDPPA);4,4′-bis[N-(4-diphenylaminophenyl)-N-phenylamino]biphenyl (DPAB);4,4′-bis(N-{4-[N′-(3-methylphenyl)-N′-phenylamino]phenyl}-N-phenylamino)biphenyl(DNTPD), and 1,3,5-tris[N-(4-diphenylaminophenyl)-N-phenylamino]benzene(DPA3B).

Examples of the carbazole derivatives which can be used for thecomposite material include3-[N-(9-phenylcarbazol-3-yl)-N-phenylamino]-9-phenylcarbazole (PCzPCA1);3,6-bis[N-(9-phenylcarbazol-3-yl)-N-phenylamino]-9-phenylcarbazole(PCzPCA2), and3-[N-(1-naphtyl)-N-(9-phenylcarbazol-3-yl)amino]-9-phenylcarbazole(PCzPCN1). Moreover, 4,4′-di(N-carbazolyl)biphenyl (CBP);1,3,5-tris[4-(N-carbazolyl)phenyl]benzene (TCPB);9-[4-(N-carbazolyl)]phenyl-10-phenylanthracene (CzPA);1,4-bis[4-(N-carbazolyl)phenyl]-2,3,5,6-tetraphenylbenzene; or the likecan also be used.

Examples of the aromatic hydrocarbon which can be used for the compositematerial include 2-tert-butyl-9,10-di(2-naphthyl)anthracene (t-BuDNA);2-tert-butyl-9,10-di(1-naphthyl)anthracene;9,10-bis(3,5-diphenylphenyl)anthracene (DPPA);2-tert-butyl-9,10-bis(4-phenylphenyl)anthracene (t-BuDBA);9,10-di(2-naphthyl)anthracene (DNA); 9,10-diphenylanthracene (DPAnth);2-tert-butylanthracene (t-BuAnth);9,10-bis(4-methyl-1-naphthyl)anthracene (DMNA);2-tert-butyl-9,10-bis[2-(1-naphthyl)phenyl]anthracene;9,10-bis[2-(1-naphthyl)phenyl]anthracene;2,3,6,7-tetramethyl-9,10-di(1-naphthyl)anthracene;2,3,6,7-tetramethyl-9,10-di(2-naphthyl)anthracene; 9,9′-bianthryl;10,10′-diphenyl-9,9′-bianthryl;10,10′-bis(2-phenylphenyl)-9,9′-bianthryl;10,10′-bis[(2,3,4,5,6-pentaphenyl)phenyl]-9,9′-bianthryl; anthracene;tetracene; rubrene; perylene, and 2,5,8,11-tetra(tert-butyl)perylene.Besides these compounds, pentacene, coronene, or the like can also beused. In particular, use of an aromatic hydrocarbon which has a holemobility of greater than or equal to 1×10⁻⁶ cm²/Vs and has 14 to 42carbon atoms is more preferable.

It is to be noted that the aromatic hydrocarbon which can be used forthe composite material may have a vinyl skeleton. Examples of thearomatic hydrocarbon having a vinyl skeleton include4,4′-bis(2,2-diphenylvinyl)biphenyl (DPVBi) and9,10-bis[4-(2,2-diphenylvinyl)phenyl]anthracene (DPVPA).

Examples of the substance used for the composite material furtherinclude high molecular compounds such as poly(N-vinylcarbazole) (PVK),poly(4-vinyltriphenylamine) (PVTPA),poly[N-(4-{N′-[4-(4-diphenylamino)phenyl]phenyl-N′-phenylamino}phenyl)methacrylamide](PTPDMA); and poly[N,N′-bis(4-butylphenyl)-N,N′-bis(phenyl)benzidine](Poly-TPD).

The hole-transporting layer 112 is a layer that includes a substancehaving a high hole-transporting property. Examples of the substancehaving a high hole-transporting property include aromatic aminecompounds such as 4,4′-bis[N-(1-naphthyl)-N-phenylamino]biphenyl (NPB),N,N′-bis(3-methylphenyl)-N,N′-diphenyl-[1,1′-biphenyl]-4,4′-diamine(TPD), 4,4′,4″-tris(N,N-diphenylamino)triphenylamine (TDATA),4,4′,4″-tris[N-(3-methylphenyl)-N-phenylamino]triphenylamine (m-MTDATA),and 4,4′-bis[N-(spiro-9,9′-bifluoren-2-yl)-N-phenylamino]-1,1′-biphenyl(BSPB). These substances described here mainly are substances eachhaving a hole mobility of greater than or equal to 10⁻⁶ cm²/Vs It is tobe noted that any substance other than the above substances may also beused as long as it is a substance in which the hole-transportingproperty is higher than the electron-transporting property. The layerthat includes a substance having a high hole-transporting property isnot limited to a single layer, and may be a stack of two or more layerseach including the aforementioned substance.

Alternatively, a high molecular compound such as poly(N-vinylcarbazole)(PVK) or poly(4-vinyltriphenylamine) (PVTPA) can also be used for thehole-transporting layer 112.

The light-emitting layer 113 is a layer that includes a substance havinga high light-emitting property. In the light-emitting element of thisembodiment mode, the light-emitting layer 113 includes any of theanthracene derivatives of the present invention that are described inEmbodiment Mode 1. The anthracene derivatives of the present inventionare suitable for application in a light-emitting element as a substancehaving a high light-emitting property since the anthracene derivativesof the present invention emit blue light.

The electron-transporting layer 114 is a layer that includes a substancehaving a high electron-transporting property. For example, it ispossible to employ a layer made of a metal complex or the like having aquinoline or benzoquinoline skeleton, such astris(8-quinolinolato)aluminum (Alq),tris(4-methyl-8-quinolinolato)aluminum (Almq₃),bis(2-methyl-8-quinolinolato)(4-phenylphenolato)aluminum (BAlq).Alternatively, a metal complex or the like having an oxazole-based orthiazole-based ligand, such as bis[2-(2-hydroxyphenyl)benzoxazolato]zinc(Zn(BOX)₂) or bis[2-(2-hydroxyphenyl)-benzothiazolato]zinc (Zn(BTZ)₂)can be used. In stead of the metal complex,2-(4-biphenylyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole (PBD),1,3-bis[5-(p-tert-butylphenyl)-1,3,4-oxadiazol-2-yl]benzene (OXD-7),3-(4-biphenylyl)-4-phenyl-5-(4-tert-butylphenyl)-1,2,4-triazole (TAZ),bathophenanthroline (BPhen), bathocuproine (BCP), or the like can alsobe used. The substances described here mainly are substances each havingan electron mobility of greater than or equal to 10⁻⁶ cm²/Vs. It is tobe noted that any substance other than the above substances may also beused as long it is a substance in which the electron-transportingproperty is higher than the hole-transporting property.

Furthermore, the electron-transporting layer 114 is not limited to asingle layer, and may be a stack of two or more layers each includingthe aforementioned substance.

For the electron-transporting layer 114, a high molecular compound canbe used. For example,poly[(9,9-dihexylfluorene-2,7-diyl)-co-(pyridin-3,5-diyl)] (PF-Py),poly[(9,9-dioctylfluorene-2,7-diyl)-co-(2,2′-bipyridin-6,6′-diyl)](PF-BPy), or the like can be used.

The second electrode 103 can be formed using any of metal, alloy, and anelectrically conductive compound each having a low work function (3.8 eVor lower), a mixture of them, or the like. Specific examples of suchcathode materials include elements belonging to Group 1 or 2 of theperiodic table, i.e., alkali metals such as lithium (Li) and cesium (Cs)and alkaline earth metals such as magnesium (Mg), calcium (Ca), andstrontium (Sr); alloys of them (e.g., MgAg and AlLi); rare earth metalssuch as europium (Eu) and ytterbium (Yb), and alloys of them. However,when the electron-injecting layer is provided between the secondelectrode 103 and the electron-transporting layer, any of a variety ofconductive materials such as Al, Ag, ITO, and ITO containing silicon orsilicon oxide can be used for the second electrode 103 regardless of itswork function. Films of these electrically conductive materials can beformed by a sputtering method, an ink-jet method, a spin coating method,or the like.

As the layer having a function of promoting electron injection, analkali metal, an alkaline earth metal, or a compound thereof, such aslithium fluoride (LiF), cesium fluoride (CsF), or calcium fluoride(CaF₂) can be used. Alternatively, a layer that includes a substancehaving an electron-transporting property and an alkali metal, analkaline earth metal, or a compound thereof (Alq including magnesium(Mg) for example) can be used. The use of such a layer as anelectron-injecting layer is advantageous because electron injection fromthe second electrode 103 proceeds efficiently.

Any of a variety of methods can be employed for forming the layer 102including an organic compound regardless of whether it is a dry processor a wet process. For example, a vacuum evaporation method, an ink-jetmethod, a spin coating method, or the like can be used. Further,different deposition methods may be employed for each electrode orlayer.

Similarly, the electrodes may be formed by a wet process such as asol-gel process or by a wet process using a metal paste. Alternatively,the electrodes may be formed by a dry process such as a sputteringmethod or a vacuum evaporation method.

Hereinafter, a specific fabrication method of a light-emitting elementis described. In the case where a light-emitting element of the presentinvention is applied to a display device and a light-emitting layer foreach color is fanned separately, it is preferable to form thelight-emitting layer by a wet process. By forming the light-emittinglayers by a wet process such as an inkjet method, the formation of thelight-emitting layers for the respective colors becomes easy even when alarge substrate is used.

For example, in the structure described in this embodiment mode, thefirst electrode may be formed by a sputtering method, which is a dryprocess; the hole-injecting layer may be formed by an inkjet method or aspin coating method, which are wet processes; the hole-transportinglayer may be formed by a vacuum evaporation method, which is a dryprocess; the light-emitting layer may be formed by an inkjet method,which is a wet process; the electron-injecting layer may be formed by aco-deposition method, which is a dry process; and the second electrodemay be formed by an inkjet method or a spin coating method, which arewet processes. Alternatively, the first electrode may be formed by aninkjet method, which is a wet process; the hole-injecting layer may beformed by a vacuum evaporation method, which is a dry process; thehole-transporting layer may be formed by an inkjet method or a spincoating method, which are wet processes; the light-emitting layer may beformed by an inkjet method, which is a wet process; theelectron-injecting layer may be formed by an inkjet method or a spincoating method, which are wet processes; and the second electrode may beformed by an inkjet method or a spin coating method, which are wetprocesses. It is to be noted that a wet process and a dry process can becombined as appropriate, without being limited to the above methods.

Further alternatively, for example, the first electrode can be formed bya sputtering method, which is a dry process; the hole-injecting layerand the hole-transporting layer can be formed by an inkjet method or aspin coating method, which are wet processes; the light-emitting layercan be formed by an inkjet method, which is a wet process; theelectron-injecting layer can be formed by a vacuum evaporation method,which is a dry process; and the second electrode can be formed by avacuum evaporation method, which is a dry process. In other words, on asubstrate provided with the first electrode having a desired shape, awet process can be employed for the formation of the hole-injectinglayer to the light-emitting layer, and a dry process can be employed forthe formation of the electron-injecting layer to the second electrode.In this method, the hole-injecting layer to the light-emitting layer canbe formed at atmospheric pressure and the light-emitting layers forrespective colors can be easily formed separately. In addition, from theelectron-injecting layer to the second electrode can be formed in vacuumconsistently. Therefore, the process can be simplified and productivitycan be improved.

In the light-emitting element of the present invention having thestructure as described above, the potential difference generated betweenthe first electrode 101 and the second electrode 103 makes a currentflow, whereby holes and electrons are recombined in the light-emittinglayer 113 that is a layer including a high light-emitting property andthus light is emitted. That is, a light-emitting region is formed in thelight-emitting layer 113.

It is to be noted that the structure of the layers provided between thefirst electrode 101 and the second electrode 103 is not limited to theabove, and may be any structure as long as the light-emitting region forrecombination of holes and electrons is positioned away from the firstelectrode 101 and the second electrode 103 so as to suppress quenchingwhich would otherwise be caused by the proximity of the light-emittingregion to metal.

That is, there is no particular limitation on the stacked structure ofthe layers. It is acceptable as long as the layer including any of theanthracene derivatives of the present invention is freely combined withthe layers each including a substance having a highelectron-transporting property, a substance having a highhole-transporting property, a substance having a high electron-injectingproperty, a substance having a high hole-injecting property, a bipolarsubstance (a substance having high electron-transporting and ahole-transporting property), or a hole-blocking material.

As shown in this embodiment mode, each of the anthracene derivatives ofthe present invention can be used for a light-emitting layer without anyneed for any other light-emitting substance, since the anthracenederivatives emit blue light.

Since each of the anthracene derivatives of the present invention have ahigh quantum yield, a light-emitting element that uses any of theanthracene derivatives of the present invention for a light-emittingelement can be made to have high emission efficiency. Also, since theanthracene derivatives of the present invention are stable with respectto repetitive redox reactions, a light-emitting element that uses any ofthe anthracene derivatives can be made to have a long life.

Since the light-emitting element that uses any of the anthracenederivatives of the present invention can emit blue light at highefficiency, the light-emitting element is suitable for use in afull-color display. Further, since the light-emitting element can emitblue light with a long life, the light-emitting element is suitable foruse in a full-color display. In particular, blue light-emitting elementsare less developed in terms of life and efficiency than greenlight-emitting elements and red light-emitting elements; therefore, bluelight-emitting elements having good characteristics are expected. Thelight-emitting element that uses any of the anthracene derivatives ofthe present invention can emit blue light at high efficiency and a longlife, and thus is suitable for a full-color display.

Embodiment Mode 4

In Embodiment Mode 4, a light-emitting element having a differentstructure from that described in Embodiment Mode 3 is described.

In this embodiment mode, the light-emitting layer 113 shown inEmbodiment Mode 2 has a structure in which any of the anthracenederivatives of the present invention is dispersed into anothersubstance, whereby light emission can be obtained from the anthracenederivative of the present invention. Since the anthracene derivatives ofthe present invention emit blue light, a light-emitting element thatemits blue light can be obtained.

Any of a variety of materials can be used as the substance in which oneof the anthracene derivatives of the present invention is dispersed. Inaddition to the substance having a high hole-transporting property andthe substance having a high electron-transporting property, which aredescribed in Embodiment Mode 2, 4,4′-di(N-carbazolyl)-biphenyl (CBP),2,2′,2″-(1,3,5-benzenetriyl)-tris[1-phenyl-1H-benzimidazole] (TPBI),9,10-di(2-naphthyl)anthracene (DNA),2-tert-butyl-9,10-di(2-naphthyl)anthracene (t-BuDNA), or the like can beused. Further, as the substance in which one of the anthracenederivatives of the present invention is dispersed, a high molecularcompound can be used. For example, poly(N-vinylcarbazole) (PVK);poly(4-vinyltriphenylamine) (PVTPA);poly[N-(4-{N′-[4(4-diphenylamino)phenyl]phenyl-Ni-phenylamino}phenyl)methacrylamide](PTPDMA); poly[N,N′-bis(4-butylphenyl)-N,N′-bis(phenyl)benzidine](Poly-TPD), poly[(9,9-dihexylfluorene-2,7-diyl)-co-(pyridine-3,5-di yl)](PF-Py);poly[(9,9-dioctylfluorene-2,7-diyl)-co-(2,2′-bipyridine-6,6′-diyl)](PF-BPy), or the like can be used.

Since the anthracene derivatives of the present invention have highemission efficiency, a light-emitting element with high emissionefficiency can be obtained by use of any of the anthracene derivativesof the present invention in a light-emitting element. Also, by use ofany of the anthracene derivatives of the present invention in alight-emitting element, a light-emitting element with a long life can beobtained.

Further, since a light-emitting element that uses any of the anthracenederivatives of the present invention can emit blue light at highefficiency, the light-emitting element can be suitable for use in afull-color display. In addition, since the light-emitting element thatuses any of the anthracene derivatives of the present invention can emitblue light with a long life, the light-emitting element can be suitablefor use in a full-color display.

It is to be noted that, regarding the layers other than thelight-emitting layer 113, the structure shown in Embodiment Mode 3 canbe as appropriate used.

Embodiment Mode 5

In Embodiment Mode 5, a light-emitting element with a structuredifferent from the structures described in Embodiment Modes 3 and 4 isdescribed.

The light-emitting layer 113 shown in Embodiment Mode 3 has a structurein which a light-emitting substance is dispersed into any of theanthracene derivatives of the present invention, whereby light emissionfrom the light-emitting substance can be obtained.

When any of the anthracene derivatives of the present invention is usedas a material in which another light-emitting substance is dispersed, acolor generated by the light-emitting substance can be obtained.Further, a mixture of a color generated by the anthracene derivative ofthe present invention and a color generated by the light-emittingsubstance dispersed in the anthracene derivative can also be obtained.

In this case, any of a variety of materials can be used as thelight-emitting substance dispersed in the anthracene derivative of thepresent invention. Specifically, examples of fluorescent substances thatemit fluorescence include N,N-diphenylquinacridon (DPQd), coumarin 6,coumarin 545T,4-(dicyanomethylene)-2-methyl-6-(p-dimethylaminostyryl)-4H-pyran (DCM1),4-(dicyanomethylene)-2-methyl-6-(julolidin-4-yl-vinyl)-4H-pyran (DCM2),N,N-dimethylquinacridone (DMQd),{2-(1,1-dimethylethyl)-6-[2-(2,3,6,7-tetrahydro-1,1,7,7-tetramethyl-1H,5H-benzo[ij]quinolizin-9-yl)ethenyl]-4H-pyran-4-ylidene}propanedinitrile(DCJTB), 5,12-diphenyltetracene (DPT),4-(9H-carbazol-9-yl)-4′-(10-phenyl-9-anthryl)triphenyl amine (YGAPA),4,4′-(2-tert-butylanthracen-9,10-diyl)bis{N-[4-(9H-carbazol-9-yl)phenyl]-N-phenylaniline}(YGABPA),N,9-diphenyl-N-[4-(10-phenyl-9-anthryl)phenyl]-9H-carbazol-3-amine(PCAPA),N,N″-(2-tert-butylanthracene-9,10-diyldi-4,1-phenylene)bis[N,N,N′-triphenyl-1,4-phenylenediamine](DPABPA),N,N′-bis[4-(9H-carbazol-9-yl)phenyl]-N,N-diphenylstilbene-4,4′-diamine(YGA2S), N-[4-(9H-carbazol-9-yl)phenyl]-N-phenylstilben-4-amine (YGAS),Ar-diphenyl-N/N′-bis(9-phenylcarbazol-3-yl)stilben-4,4′-diamine (PCA2S),4,4′-bis(2,2-diphenylvinyl)biphenyl (DPVBi),2,5,8,11-tetra(tert-butyl)perylene (TBP), perylene, rubrene, and1,3,6,8-tetraphenylpyrene. Moreover, examples of phosphorescentsubstances that emit phosphorescence include(acetylacetonato)bis[2,3-bis(4-fluorophenyl)quinoxalinato] iridium(III)(Ir(Fdpq)₂(acac)), and(2,3,7,8,12,13,17,18-octaethyl-21H,23H-porphyrinato)platinum(II)(PtOEP).

It is to be noted that, regarding the layers other than thelight-emitting layer 113, the structure shown in Embodiment Mode 3 canbe appropriately used.

Embodiment Mode 6

In Embodiment Mode 6, a light-emitting element with a structuredifferent from those of Embodiment Modes 3 to 5 is described.

Anthracene derivatives of the present invention each have ahole-transporting property. Therefore, a layer including any of theanthracene derivatives of the present invention can be used between ananode and a light-emitting layer. Specifically, the anthracenederivatives of the present invention can be used in the hole-injectinglayer 111 and/or the hole-transporting layer 112 described in EmbodimentMode 2.

Also, in the case of applying any of the anthracene derivatives of thepresent invention as the hole-injecting layer 111, it is preferable tocompose the anthracene derivative of the present invention and aninorganic compound having an electron accepting property with respect tothe anthracene derivative of the present invention. By use of such acomposite material, the carrier density increases, which contributes toimprovement of the hole-injecting property and hole-transportingproperty. Also, in the case of using the composite material in thehole-injecting layer 111, the hole-injecting layer 111 can achieve anohmic contact with the first electrode 101; therefore, a material of thefirst electrode 101 can be selected regardless of work function.

As the inorganic compound used for the composite material, an oxide of atransition metal is preferably used. Moreover, an oxide of metalsbelonging to Groups 4 to 8 in the periodic table can be used.Specifically, it is preferable to use vanadium oxide, niobium oxide,tantalum oxide, chromium oxide, molybdenum oxide, tungsten oxide,manganese oxide, or rhenium oxide, because of its high electronaccepting property. Among them, use of molybdenum oxide is especiallypreferable since it is stable in the air, has a low hygroscopicproperty, and is easily treated.

It is to be noted that this embodiment mode can be combined with anyother embodiment mode as appropriate.

Embodiment Mode 7

In Embodiment Mode 7, a light-emitting element having a structuredifferent from the structures described in Embodiment Modes 3 to 6 isdescribed using FIG. 2.

In the light-emitting element described in this embodiment mode, a firstlayer 121 and a second layer 122 are provided in the light-emittinglayer 113 of the light-emitting element described in Embodiment Mode 2.

The light-emitting layer 113 is a layer that includes a substance havinga high light-emitting property. In the light-emitting element of thepresent invention, the light-emitting layer has the first layer 121 andthe second layer 122. The first layer 121 includes a first organiccompound and an organic compound having a hole-transporting property,and the second layer 122 includes a second organic compound and anelectron-transporting organic compound. The first layer 121 is providedon the first electrode side of the second layer 122, in other words, onthe anode side of the second layer 122.

Each of the first organic compound and the second organic compound is asubstance having a high light-emitting property, for which any of avariety of materials can be used. Specifically, examples of fluorescentsubstances that emit fluorescence include N,N′-diphenylquinacridon(DPQd), coumarin 6, coumarin 545T,4-(dicyanomethylene)-2-methyl-6-(p-dimethylaminostyryl)-4H-pyran (DCM1),4-(dicyanomethylene)-2-methyl-6-(julolidin-4-yl-vinyl)-4H-pyran (DCM2),N,N-dimethylquinacridone (DMQd),{2-(1,1-dimethylethyl)-6-[2-(2,3,6,7-tetrahydro-1,1,7,7-tetramethyl-1H,5H-benzo[ij]quinolizin-9-yl)ethenyl]-4H-pyran-4-ylidene}propanedinitrile(DCJTB), 5,12-diphenyltetracene (DPT),4-(9H-carbazol-9-yl)-4′-(10-phenyl-9-anthryl)triphenylamine (YGAPA),4,4′-(2-tert-butylanthracen-9,10-diyl)bis{N-[4-(9H-carbazol-9-yl)phenyl]-N-phenylaniline}(YGABPA),N,9-diphenyl-N44-(10-phenyl-9-anthryl)phenyl′-9H-carbazole-3-amine(PCAPA),N,N″-(2-tert-butylanthracene-9,10-diyldi-4,1-phenylene)bis[N,N′,N′-triphenyl-1,4-phenylenediamine](DPABPA),N,N′-bis[4-(9H-carbazol-9-yl)phenyl]-N,N′-diphenylstilbene-4,4′-diamine(YGA2S), N-[4-(9H-carbazol-9-yl)phenyl]-N-phenylstilbene-4-amine (YGAS),N,N′-diphenyl-N,N′-bis(9-phenylcarbazol-3-yl)stilbene-4,4′-diamine(PCA2S), 4,4′-bis(2,2-diphenylvinyl)biphenyl (DPVBi),2,5,8,11-tetra(tert-butyl)perylene (TBP), perylene, rubrene, and1,3,6,8-tetraphenylpyrene. The first organic compound and the secondorganic compound may be the same or different from one another.

The organic compound having a hole-transporting property included in thefirst layer 121 is a substance in which the hole-transporting propertyis higher than the electron-transporting property, and any of theanthracene derivatives of the present invention can be preferably usedas this organic compound. The organic compound having anelectron-transporting property included in the second layer 122 is asubstance in which the electron-transporting property is higher than thehole-transporting property.

A mechanism of the light-emitting element of the present inventionhaving the above-described structure is described below using FIG. 2.

In FIG. 2, holes injected from the first electrode 101 are injected intothe first layer 121. The holes injected into the first layer 121 aretransported through the first layer 121 and further injected into thesecond layer 122. At this time, the organic compound having anelectron-transporting property included in the second layer 122 is asubstance in which having the electron-transporting property is higherthan the hole-transporting property, and thus, the holes injected intothe second layer 122 become difficult to move. Consequently, a largenumber of holes are present near the interface between the first layer121 and the second layer 122. In addition, occurrence of a phenomenon inwhich holes reach the electron-transporting layer 114 withoutrecombining with electrons can be suppressed.

On the other hand, electrons injected from the second electrode 103 areinjected into the second layer 122. The electrons injected into thesecond layer 122 are transported through the second layer 122 andfurther injected into the first layer 121. At this time, the organiccompound having a hole-transporting property included in the first layer121 is a substance in which having the hole-transporting property ishigher than the electron-transporting property, and thus, the electronsinjected into the first layer 121 become difficult to move.Consequently, a large number of electrons are present near the interfacebetween the first layer 121 and the second layer 122. In addition,occurrence of a phenomenon in which electrons reach thehole-transporting layer 112 without recombining with holes can besuppressed.

As described above, a large number of holes and electrons are present ina region in the vicinity of the interface between the first layer 121and the second layer 122, so that recombination probability in theregion in the vicinity of the interface can be increased. In otherwords, the light-emitting region is formed in the vicinity of the centerof the light-emitting layer 113. As a result, occurrence of a phenomenonin which holes reach the electron-transporting layer 114 withoutrecombining with electrons or electrons reach the hole-transportinglayer 112 without recombining with holes can be suppressed, so thatreduction in recombination probability can be prevented. Thus, reductionof carrier balance over time can be prevented, which leads toimprovement of reliability.

In order that holes and electrons are injected into the first layer 121,the organic compound having a hole-transporting property can be oxidizedand reduced, and it is preferred that it have the highest occupiedmolecular orbital level (HOMO level) of greater than or equal to −6.0 eVand less than or equal to −5.0 eV as well as the lowest unoccupiedmolecular orbital level (LUMO level) of greater than or equal to −3.0 eVand less than or equal to −2.0 eV. Accordingly, use of the anthracenederivatives of the present invention is preferable.

Similarly, in order that holes and electrons are injected into thesecond layer 122, it is necessary that the organic compound having ahole-transporting property is an organic compound which can be oxidizedand reduced, and it is preferred that it have the HOMO level of greaterthan or equal to −6.0 eV and less than or equal to −5.0 eV as well asthe LUMO level of greater than or equal to −3.0 eV and less than orequal to −2.0 eV.

As such an organic compound which can be oxidized or reduced, atricyclic polyacene derivative, a tetracyclic polyacene derivative, apentacyclic polyacene derivative, or a hexacyclic polyacene derivativeis used. Specifically, an anthracene derivative, a phenanthrenederivative, a pyrene derivative, a chrysene derivative, adibenzo[g,p]chrysene derivative, or the like is used. For example, as ancompound having an electron-transporting property, which can be used forthe second layer, 9-[4-(N-carbazolyl)]phenyl-10-phenylanthracene (CzPA),3,6-diphenyl-9-[4-(10-phenyl-9-anthryl)phenyl]-9H-carbazole (DPCzPA),9,10-bis(3,5-diphenylphenyl)anthracene (DPPA),9,10-di(2-naphthyl)anthracene (DNA),2-tert-butyl-9,10-di(2-naphthyl)anthracene (t-BuDNA), 9,9′-bianthryl(BANT), 9,9′-(stilben-3,3′-diyl)diphenanthrene (DPNS),9,9′-(stilben-4,4′-diyl)diphenanthrene (DPNS2),3,3′,3″-(benzene-1,3,5-triyl)tripyrene (TPB3) and the like can be given.

As described above using FIG. 2, the light-emitting element of thepresent invention is structured so that holes are injected into thesecond layer 122 from the first layer 121. Thus, it is preferable thatthe difference in HOMO level between that of the anthracene derivativeused for the organic compound having a hole-transporting property andthat of the organic compound having an electron-transporting property issmall. Further, since the light-emitting element of the presentinvention is structured so that electrons are injected into the firstlayer 121 from the second layer 122, it is preferable that thedifference in LUMO level between that of the anthracene derivative usedfor the organic compound having a hole-transporting property and that ofthe organic compound having an electron-transporting property is small.If the difference in HOMO level between that of organic compound havinga hole-transporting property and that of the organic compound having anelectron-transporting property is, the light-emitting region is formedmore on the first layer side or the second layer side. Similarly, if thedifference in LUMO level between that of the organic compound having ahole-transporting property and that of the organic compound having anelectron-transporting property is large, the light-emitting region isformed more on the first layer side or the second layer side.Accordingly, the difference between the HOMO level of the anthracenederivative used for the organic compound having a hole-transportingproperty and the HOMO level of the organic compound having anelectron-transporting property is preferably 0.3 eV or less, and morepreferably 0.1 eV or less. The LUMO level of the anthracene derivativeused for the organic compound having a hole-transporting property andthe LUMO level of the organic compound having an electron-transportingproperty is preferably 0.3 eV or less, and more preferably 0.1 eV orless.

Since light is emitted from the light-emitting element by recombinationof electrons and holes, it is preferable that the organic compound usedfor the light-emitting layer 113 be stable with respect to repetitiveredox reactions. In other words, it is preferable that the organiccompound be able to be reversibly oxidized and reduced. It is preferablethat, in particular, the organic compound having a hole-transportingproperty and the organic compound having an electron-transportingproperty be stable with respect to repetitive redox reactions.Accordingly, any of the anthracene derivatives of the present inventionis suitable for use as the organic compound having a hole-transportingproperty. Whether the organic compounds are stable with respect torepetitive redox reactions or not can be confirmed by cyclic voltammetry(CV) measurement.

Specifically, whether the organic compounds are stable with respect torepetitive redox reactions or not can be confirmed by measurement ofchanges in an oxidation peak potential (E_(pa)) of an oxidation reactionof the organic compound or a reduction peak potential (E_(pc)) of anreduction reaction, changes in the peak shape, and the like. In theorganic compound having a hole-transporting property and the organiccompound having an electron-transporting property used for thelight-emitting layer 113, the amount of change in the intensity of theoxidation peak potential or the intensity of the reduction peakpotential is preferably less than 50%, and more preferably less than30%. In other words, for example, a peak intensity of 50% or higher,more preferably, a peak intensity of 70% is kept, even if the oxidationpeak potential decreases. In addition, the amount of change of thevalues of the oxidation peak potential or the reduction peak potentialis preferably 0.05 V or lower, more preferably, 0.02 V or lower.

When the substance having a high light-emitting property included in thefirst layer and the substance having a high light-emitting propertyincluded in the second layer are the same, light can be emitted in thevicinity of the center of the light-emitting layer. In contrast, whenthe substance having a high light-emitting property included in thefirst layer and the substance having a high light-emitting propertyincluded in the second layer are different, there is a possibility thatlight is emitted from only one of the first layer and the second layer.Therefore, it is preferred that the substance having a light-emittingproperty included in the first layer and the substance having alight-emitting property included in the second layer be the same.

In the light-emitting element described in this embodiment mode, alight-emitting region is formed in the vicinity of the center of thelight-emitting layer, not at the interface between the light-emittinglayer and the hole-transporting layer or at the interface between thelight-emitting layer and the electron-transporting layer. Accordingly,the light-emitting element is not affected by deterioration due toproximity of the light-emitting region to the hole-transporting layer orthe electron-transporting layer. Therefore, the light-emitting elementwith a small amount of deterioration and a long life can be obtained.Furthermore, since the light-emitting layer in the light-emittingelement of the present invention includes the compound that is stablewith respect to repetitive redox reactions, there is littledeterioration of the light-emitting layer after light emission byrecombination of holes and electrons are repeated. Therefore, alight-emitting element that has a longer life can be obtained.

Further, since the anthracene derivatives of the present invention aresuitable for excitation of a substance having a high light-emittingelement property that exhibits blue to blue green light, the elementstructure shown in this embodiment mode is particularly effective for alight-emitting element for bluish color and a light-emitting element forblue-greenish color. Blue color is needed for fabrication of afull-color display, and a problem of the deterioration can be solved byapplying the present invention. It is natural that the anthracenederivatives of the present invention may be used for a light-emittingelement of a green or red color. This embodiment mode can be combinedwith any other embodiment mode as appropriate.

Embodiment Mode 8

In Embodiment Mode 7, a light-emitting element in which a plurality oflight-emitting units according to the present invention is stacked(hereinafter, referred to as a stacked type element) is described usingFIG. 3. This light-emitting element is a stacked type light-emittingelement that has a plurality of light-emitting units between a firstelectrode and a second electrode. Each light-emitting unit can have astructure similar to that of the layer 102 including an organic compounddescribed in Embodiment Modes 2 to 6 can be used for. In other words,the light-emitting elements described in Embodiment Modes 2 to 6 areeach a light-emitting element having one light-emitting unit. In thisembodiment mode, a light-emitting element having a plurality oflight-emitting units is described.

In FIG. 3, a first light-emitting unit 511 and a second light-emittingunit 512 are stacked between a first electrode 501 and a secondelectrode 502, a charge generation layer 513 is provided between thefirst light-emitting unit 511 and the second light-emitting unit 512.Electrodes similar to those described in Embodiment Mode 2 can beapplied to the first electrode 501 and the second electrode 502. Thefirst light-emitting unit 511 and the second light-emitting unit 512 mayhave the same structure or different structures, and a structure similarto those described in Embodiment Modes 2 to 6 can be applied.

The charge generation layer 513 includes a composite material of anorganic compound and metal oxide. The composite material of an organiccompound and metal oxide is described in Embodiment Mode 2 or 5, andincludes an organic compound and metal oxide such as vanadium oxide,molybdenum oxide, or tungsten oxide. As the organic compound, a varietyof compounds such as an aromatic amine compound, a carbazole derivative,aromatic hydrocarbon, and a high molecular compound (oligomer,dendrimer, polymer, or the like) can be used. An organic compound havinga hole mobility of greater than or equal to 1×10⁻⁶ cm²/Vs is preferablyapplied as the organic compound. However, other substances than thesecompounds may also be used as long as it is a substance in which thehole-transporting property thereof is higher than theelectron-transporting property. The composite material of an organiccompound and metal oxide is superior in carrier-injecting property andcarrier-transporting property; accordingly, low-voltage driving andlow-current driving can be realized.

It is to be noted that the charge generation layer 513 may be formed bya combination of a composite material of an organic compound and metaloxide with another material. For example, the charge generation layer513 may be formed with a combination of a layer including the compositematerial of an organic compound and metal oxide with a layer includingone compound selected among electron donating substances and a compoundhaving a high electron-transporting property. Further, the chargegeneration layer 513 may be formed with a combination of a layerincluding the composite material of an organic compound and metal oxidewith a transparent conductive film.

In any case, the charge generation layer 513 interposed between thefirst light-emitting unit 511 and the second light-emitting unit 512 isacceptable, as long as electrons are injected to one light-emitting unitand holes are injected to the other light-emitting unit when a voltageis applied between the first electrode 501 and the second electrode 502.

In this embodiment mode, the light-emitting element having twolight-emitting units is described; however, the present invention can beapplied to a light-emitting element in which three or morelight-emitting units are stacked, similarly. By arranging a plurality oflight-emitting units between a pair of electrodes in such a manner thatthe plurality of light-emitting units is partitioned with a chargegeneration layer, high luminance emission can be realized at a lowcurrent density, which contributes to enhancement of the life of thelight-emitting element. For example, when the light-emitting element isapplied to a lighting device, voltage drop due to resistance of anelectrode material can be suppressed, which leads to uniform emission ina large area. In other words, a light-emitting device capable oflow-voltage driving and low-power consuming can be realized.

This embodiment mode can be combined with any other embodiment mode asappropriate.

Embodiment Mode 9

In Embodiment Mode 9, a light-emitting device manufactured using any ofthe anthracene derivatives of the present invention is described.

In this embodiment mode, a light-emitting device manufactured using anyof the anthracene derivatives of the present invention is describedusing FIGS. 4A and 4B.

FIG. 4A is a top view illustrating a light-emitting device, and FIG. 4Bis a cross-sectional view of FIG. 4A taken along lines A-A′ and B-B′.The light-emitting device have a driver circuit portion (source sidedriver circuit) 401, a pixel portion 402, and a driver circuit portion(gate side driver circuit) 403 which are indicated by dotted lines.Reference numerals 404 and 405 denote a sealing substrate and a sealingmaterial, respectively. A portion surrounded by the sealing material 405corresponds to a space 407.

A leading wiring 408 is a wiring for transmitting signals to be inputtedto the source side driver circuit 401 and the gate side driver circuit403, and this wiring 408 receives a video signal, a clock signal, astart signal, a reset signal, and the like from a flexible printedcircuit (FPC) 409 which is an external input terminal. It is to be notedthat only the FPC is illustrated in this case; however, the FPC may beprovided with a printed wiring board (PWB). The category of thelight-emitting device in this specification includes not only alight-emitting device itself but also a light-emitting device attachedwith an FPC or a PWB.

Next, a cross-sectional structure is described using FIG. 4B. The drivercircuit portion and the pixel portion are formed over an elementsubstrate 410. In this case, one pixel in the pixel portion 402 and thesource side driver circuit 401 which is the driver circuit portion areillustrated.

A CMOS circuit, which is a combination of an n-channel TFT 423 with ap-channel TFT 424, is formed as the source side driver circuit 401. Eachdriver circuit portion may be any of a variety of circuits such as aCMOS circuit, PMOS circuit, and an NMOS circuit. Although adriver-integration type device, in which a driver circuit is formed overthe substrate provided with the pixel portion, is described in thisembodiment mode, a driver circuit is not necessarily formed over thesame substrate as the pixel portion, but can be formed outside asubstrate.

The pixel portion 402 has a plurality of pixels, each of which includesa switching TFT 411, a current control TFT 412, and a first electrode413 which is electrically connected to a drain of the current controlTFT 412. It is to be noted that an insulator 414 is formed so as tocover end portions of the first electrode 413. In this case, theinsulator 414 is faulted using a positive photosensitive acrylic resinfilm.

The insulator 414 is formed so as to have a curved surface havingcurvature at an upper end portion or lower end portion thereof in orderto make the coverage favorable. For example, in the case of usingpositive photosensitive acrylic as a material for the insulator 414, itis preferable that the insulator 414 be formed so as to have a curvedsurface with a curvature radius (0.2 μm to 3 μm) only at the upper endportion thereof. The insulator 414 can be formed using either a negativetype which becomes insoluble in an etchant by light irradiation or apositive type which becomes soluble in an etchant by light irradiation.

A layer 416 including an organic compound and a second electrode 417 areformed over the first electrode 413. In this case, it is preferred thatthe first electrode 413 serving as an anode be formed using a high-workfunction material. For example, the first electrode 413 can be formedusing a single-layer film of an ITO film, an indium tin oxide filmcontaining silicon, an indium oxide film containing 2 to 20 wt % of zincoxide, a titanium nitride film, a chromium film, a tungsten film, a Znfilm, a Pt film, or the like; a stack of a titanium nitride film and afilm containing aluminum as its main component; a three-layer structureof a titanium nitride film, a film containing aluminum as its maincomponent, and another titanium nitride film; or the like. When thefirst electrode 413 has a stacked structure, it can have low resistanceas a wiring, form a favorable ohmic contact, and further function as ananode.

The layer 406 including an organic compound is formed by any of avariety of methods such as an evaporation method using an evaporationmask, an ink-jet method, and a spin coating method. The layer 406including an organic compound includes any of the anthracene derivativesof the present invention that are described in Embodiment Mode 1.Further, the layer 406 including an organic compound may be formed usinganother material such as a low molecular weight compound or a highmolecular compound (the category of the high molecular compound includesan oligomer and a dendrimer).

As a material used for the second electrode 417 which is formed over thelayer 406 including an organic compound and serves as a cathode, it ispreferable that a low-work function material (e.g., Al, Mg, Li, Ca, oran alloy or compound thereof such as MgAg, Mg—In, Al—Li, LiF, or CaF₂)be used. In the case where light generated in the layer 406 including anorganic compound is transmitted through the second electrode 417, thesecond electrode 417 may be formed of a stack of a metal thin filmhaving a reduced thickness and a transparent conductive film (e.g., ITO,indium oxide containing 2 to 20 wt % of zinc oxide, indium tin oxidecontaining silicon or silicon oxide, or zinc oxide (ZnO)).

The sealing substrate 404 is attached to the element substrate 410 withthe sealing material 405; thus, a light-emitting element 418 is providedin the space 407 surrounded by the element substrate 410, the sealingsubstrate 404, and the sealing material 405. It is to be noted that thespace 407 is filled with a filler such as an inert gas (e.g., nitrogenor argon) or the sealing material 405.

It is preferable that the sealing material 405 be formed of any ofepoxy-based resins and such materials permeate little moisture andoxygen as much as possible. The sealing substrate 404 can be formed of aglass substrate; a quartz substrate; or a plastic substrate includingfiberglass-reinforced plastics (FRP), polyvinyl fluoride (PVF),polyester, acrylic, or the like.

Accordingly, a light-emitting device manufactured using any of theanthracene derivatives of the present invention can be obtained.

Since any of the anthracene derivatives described in Embodiment Mode 1is used for the light-emitting device of the present invention, alight-emitting device having high performance can be obtained.Specifically, a light-emitting device having a long life can beobtained.

Also, since the anthracene derivatives of the present invention havehigh emission efficiency, a light-emitting device with low powerconsumption can be provided.

Further, since that the light-emitting element that uses any of theanthracene derivatives of the present invention can emit blue to greenlight at high efficiency, the anthracene derivatives are suitable foruse in a full-color display. Further, since the light-emitting elementthat uses any of the anthracene derivatives of the present invention canemit blue light with a long life, the anthracene derivatives aresuitable for use in full-color displays.

As described above, this embodiment mode describes an active matrixlight-emitting device in which operation of a light-emitting element iscontrolled by transistors, which may be replaced with a passive matrixlight-emitting device. FIGS. 5A and 5B show a passive matrixlight-emitting device to which the present invention is applied. FIG. 5Ais a perspective view of the light-emitting device, and FIG. 5B is across-sectional view taken along a line X-Y of FIG. 5A. In FIGS. 5A and5B, a layer 955 including an organic compound is provided between anelectrode 952 and an electrode 956 over a substrate 951. End portions ofthe electrode 952 are covered with an insulating layer 953. Then, apartition layer 954 is provided over the insulating layer 953. A sidewall of the partition layer 954 slopes so that a distance between oneside wall and the other side wall becomes narrow toward the substratesurface. In other words, a cross section taken in the direction of theshort side of the partition layer 954 is trapezoidal, and the base ofthe cross-section (a side facing in the same direction as a planedirection of the insulating layer 953 and in contact with the insulatinglayer 953) is shorter than the upper side thereof (a side facing in thesame direction as the plane direction of the insulating layer 953 andnot in contact with the insulating layer 953). The partition layer 954provided in this manner can prevent the light-emitting element frombeing defective due to static electricity or the like. In the case of apassive matrix light-emitting device, when the light-emitting deviceincludes the light-emitting element of the present invention, alight-emitting device with a long life and also a light-emitting devicewith low power consumption can be obtained.

Embodiment Mode 10

In Embodiment Mode 10, electronic devices of the present inventionincluding the light-emitting device described in Embodiment Mode 9 aredescribed. The electronic devices of the present invention include theanthracene derivatives described in Embodiment Mode 1, and have displayportions with a long life. Further, the display portions included in theelectronic devices of the present invention consume lower power.

As electronic devices including light-emitting elements fabricated usingthe anthracene derivative of the present invention, cameras such asvideo cameras or digital cameras, goggle type displays, navigationsystems, audio reproducing devices (car audio component stereo, audiocomponent stereo, or the like), computers, game machines, portableinformation terminals (mobile computers, mobile phones, portable gamemachines, electronic books, or the like), and image reproducing devicesprovided with a recording medium (specifically, a device capable ofreproducing content of a recording medium such as a Digital VersatileDisc (DVD) and provided with a display device that can display theimage), and the like are given. Specific examples of these electronicdevices are shown in FIGS. 6A to 6D.

FIG. 6A shows a television device according to the present invention,which includes a housing 9101, a supporting base 9102, a display portion9103, a speaker portion 9104, a video input terminal 9105, and the like.In the television device, the display portion 9103 has light-emittingelements similar to those described in Embodiment Modes 2 to 7, and thelight-emitting elements are arranged in matrix. The light-emittingelement is characterized by the high emission efficiency and a longlife. The display portion 9103 including the light-emitting elements hassimilar characteristics. Accordingly, in the television device, imagequality does not deteriorate much and low power consumption is achieved.Thus, deterioration compensation function circuits and power supplycircuits can be significantly reduced or downsized in the televisiondevice, which enables reduction of the size and weight of the housing9101 and supporting base 9102. In the television device according to thepresent invention, low power consumption, high image quality, and smallsize and lightweight are achieved; therefore, products suitable forliving environment can be provided. Also, since the anthracenederivatives described in Embodiment Mode 1 can emit blue to green light,full-color display is possible, and television devices having a displayportion with a long life can be provided.

FIG. 6B shows a computer according to the present invention, whichincludes a main body 9201, a housing 9202, a display portion 9203, akeyboard 9204, an external connection port 9205, a pointing device 9206,and the like. In the computer, the display portion 9203 haslight-emitting elements similar to those described in Embodiment Modes 2to 7, and the light-emitting elements are arranged in matrix. Thelight-emitting element is characterized by the high emission efficiencyand a long life. The display portion 9203 including the light-emittingelements has similar characteristics. Accordingly, in the computer,image quality does not deteriorate much and lower power consumption isachieved. Owing to these characteristics, deterioration compensationfunction circuits and power supply circuits can be significantly reducedor downsized in the computer; thus, small sized and lightweight mainbody 9201 and housing 9202 can be achieved. In the computer according tothe present invention, low power consumption, high image quality, andsmall size and lightweight are achieved; therefore, products suitablefor an environment can be supplied. Further, since the anthracenederivatives described in Embodiment Mode 1 can emit blue to green light,full-color display is possible, and computers having a display portionwith a long life can be provided.

FIG. 6C shows a mobile phone according to the present invention, whichincludes a main body 9401, a housing 9402, a display portion 9403, anaudio input portion 9404, an audio output portion 9405, an operation key9406, an external connection port 9407, an antenna 9408, and the like.In the mobile phone, the display portion 9403 has light-emittingelements similar to those described in Embodiment Modes 2 to 7, and thelight-emitting elements are arranged in matrix. The light-emittingelement is characterized by high emission efficiency and a long life.The display portion 9403 including the light-emitting elements hassimilar characteristics. Accordingly, in the mobile phone, image qualitydoes not deteriorate much and lower power consumption is achieved. Owingto these characteristics, deterioration compensation function circuitsand power supply circuits can be significantly reduced or downsized inthe mobile phone; thus, small sized and lightweight main body 9401 andhousing 9402 can be supplied. In the mobile phone according to thepresent invention, low power consumption, high image quality, and asmall size and lightweight are achieved; therefore, products suitablefor carrying can be provided. Since the anthracene derivatives describedin Embodiment Mode 1 can emit blue to green light, full-color display ispossible, and mobile phones having a display portion with a long lifecan be provided.

FIG. 6D shows a camera according to the present invention, whichincludes a main body 9501, a display portion 9502, a housing 9503, anexternal connection port 9504, a remote control receiving portion 9505,an image receiving portion 9506, a battery 9507, an audio input portion9508, operation keys 9509, an eye piece portion 9510, and the like. Inthe camera, the display portion 9502 has light-emitting elements similarto those described in Embodiment Modes 2 to 7, and the light-emittingelements are arranged in matrix. Some features of the light-emittingelement are its high emission efficiency and a long life. The displayportion 9502 including the light-emitting elements has similarcharacteristics. Accordingly, in the camera, image quality does notdeteriorate much and lower power consumption can be achieved. Suchfeatures contribute to significant reduction and downsizing of thedeterioration compensation function circuits and power supply circuitsin the camera; thus, a small sized and lightweight main body 9501 can besupplied. In the camera according to the present invention, low powerconsumption, high image quality, and small size and lightweight areachieved; therefore, products suitable for carrying can be provided.Since the anthracene derivatives described in Embodiment Mode 1 can emitblue to green light, full-color display is possible, and cameras havinga display portion with a long life can be provided.

As described above, the applicable range of the light-emitting devicesof the present invention is so wide that the light-emitting devices canbe applied to electronic devices in a variety of fields. By use of theanthracene derivatives of the present invention, electronic deviceswhich have display portions with a long life can be obtained.

Such light-emitting devices of the present invention can also be usedfor a lighting device. One mode using the light-emitting device of thepresent invention as the lighting device is described using FIG. 7.

FIG. 7 shows an example of a liquid crystal display that uses thelight-emitting device of the present invention as a backlight. Theliquid crystal display device shown in FIG. 7 includes a housing 901, aliquid crystal layer 902, a backlight 903, and a housing 904, and theliquid crystal layer 902 is connected to a driver IC 905. Thelight-emitting device of the present invention is used for the backlight903, and current is supplied through a terminal 906.

By use of the light-emitting device of the present invention as thebacklight of the liquid crystal display device, a backlight with reducedpower consumption and high emission efficiency can be provided. Thelight-emitting device of the present invention is a lighting device withplane light emission, and can have a large area. Therefore, thebacklight can have a large area, and a liquid crystal display devicehaving a large area can be obtained. Furthermore, the light-emittingdevice of the present invention has a thin shape and has low powerconsumption; thus, a thin shape and low power consumption of a displaydevice can also be achieved. Since the light-emitting device of thepresent invention has a long life, a liquid crystal display device thatuses the light-emitting device of the present invention also has a longlife.

FIG. 8 shows an example of using the light-emitting device to which thepresent invention is applied, as a table lamp which is an example of alighting device. The table lamp shown in FIG. 8 has a housing 2001 and alight source 2002, and the light-emitting device of the presentinvention is used as the light source 2002. The light-emitting device ofthe present invention has high emission efficiency and has a long life;accordingly, the table lamp also has high emission efficiency and a longlife.

FIG. 9 shows an example of using a light-emitting device to which thepresent invention is applied, as an indoor lighting device 3001. Sincethe light-emitting device of the present invention can also have a largearea, the light-emitting device of the present invention can be used asa lighting device having a large emission area. Further, thelight-emitting device of the present invention has a thin shape andconsumes low power; accordingly, the light-emitting device of thepresent invention can be used as a lighting device having a thin shapeand low-power consumption. A television device 3002 according to thepresent invention as described in FIG. 6A is placed in a room in whichthe Light-emitting device fabricated by the present invention is used asthe indoor lighting device 3001, and public broadcasting and movies canbe watched. In such a case, since both of the devices consume low power,a powerful image can be watched in a bright room without concern aboutelectricity charges.

Example 1 Synthesis Example 1

In Synthesis Example 1, a synthesis method of an anthracene derivative9-phenyl-9′-[4-10-phenyl-9-anthryl)phenyl]-3,3′-bi(9H-carbazole) (PCCPA)of the present invention represented by a structural formula (101) isspecifically described.

Step 1: Synthesis of 9-phenyl-3,3′-bi(9H-carbazole)] (PCC)

2.5 g of (10 mmol) 3-bromo-9H-carbazole, 2.9 g of (10 mmol)N-phenylcarbazol-3-boronic acid, and 152 mg of (0.50 mmol)tri(ortho-tolyl)phosphine were put into a 200 mL three-neck flask. Theair in the flask was replaced with nitrogen. To the mixture were added50 mL of dimethoxyethanol and 10 mL of an aqueous solution of potassiumcarbonate (2 mol/L). This mixture was stirred to be degassed while thepressure was reduced. After the degassing, 50 mg (0.2 mmol) of palladiumacetate was added to the mixture. This mixture was stirred at 80° C. for3 hours under a stream of nitrogen. After the stirring, about 50 mL oftoluene was added to this mixture. The mixture was stirred for about 30minutes and then washed with water and a saturated saline solution inthis order. After the washing, an organic layer was dried with magnesiumsulfate. This mixture was subjected to gravity filtration. The obtainedfiltrate was condensed to give an oily substance. The obtained oilysubstance was dissolved in toluene. This solution was subjected tosuction filtration through Florisil (produced by Wako Pure ChemicalIndustries, Ltd., Catalog No. 540-00135), alumina, and celite (producedby Wako Pure Chemical Industries, Ltd., Catalog No. 531-16855). Theobtained filtrate was concentrated to give 3.3 g of a white solid, whichwas the object of the synthesis, at a yield of 80%. A synthesis schemeof Step 1 is shown in (b-1) given below.

The solid obtained in the above Step 1 was analyzed by nuclear magneticresonance measurement (¹H NMR). The measurement result is describedbelow, and the ¹H NMR chart is shown in FIG. 10. They show that theorganic compound PCC of the present invention represented by thestructural formula (501), which is used in any of the anthracenederivatives of the present invention, was obtained in this synthesisexample.

¹H NMR (DMSO-d₆, 300 MHz): δ=7.16-7.21 (m, 1H), 7.29-7.60 (m, 8H),7.67-7.74 (m, 4H), 7.81-7.87 (m, 2H), 8.24 (d, J=7.8 Hz, 1H), 8.83 (d,J=7.8 Hz, 1H), 8.54 (d, J=1.5 Hz, 1H), 8.65 (d, J=1.5 Hz, 1H), 11.30 (s,11-1).

Step 2: Synthesis of PCCPA

1.2 g of (3.0 mmol)-9-phenyl-10-(4-bromophenyl)anthracene, 1.2 g (3.0mmol) of PCC, and 1.0 g (10 mmol) of sodium tert-butoxide were put intoa 100 mL three-neck flask. The air in the flask was replaced withnitrogen. To the mixture were added 20 mL of toluene and 0.1 mL oftri(tert-butyl)phosphine (a 10 wt % hexane solution). This mixture wasstirred to be degassed while the pressure was reduced. After thedegassing, 96 mg (0.17 mmol) of bis(dibenzylideneacetone)palladium(0)was added to the mixture. This mixture was refluxed at 110° C. for 8hours under a stream of nitrogen. After the reflux, about 50 mL oftoluene was added to this mixture. The mixture was stirred for about 30minutes and then washed with water and a saturated saline solution inthis order. After the washing, the organic layer was dried withmagnesium sulfate. This mixture was subjected to gravity filtration. Theobtained filtrate was condensed to give an oily substance. The obtainedoily substance was purified by silica gel column chromatography (adeveloping solvent was a mixed solvent of hexane:toluene=1:1). Theobtained light yellow solid was recrystallized with chloroform/hexane togive 1.2 g of a light yellow powdered solid PCCPA, which was the objectof the synthesis, at a yield of 54%. 2.4 g of the obtained light yellowpowdered solid was sublimed for purification by train sublimation. PCCPAwas heated under a pressure of 8.7 Pa, with a flow rate of argon of 3.0mL/min, at 350° C. for 15 hours to give 2.2 g of a light yellow solidPCCPA, which was the object of the synthesis, at a yield of 94%. Asynthesis scheme of Step 2 is shown in (b-2) given below.

The solid obtained in the above Step 2 was analyzed by ¹H NMR. Themeasurement result is described below, and the ¹H NMR chart is shown inFIG. 11. They show that the anthracene derivative PCCPA of the presentinvention, represented by the structural formula (220), was obtained inthis synthesis example.

¹H NMR (CDCl₃, 300 MHz): δ=7.34-7.91 (m, 3211), 8.27 (d, J=7.2 Hz, 1H),8.31 (d, J=7.5 Hz, 1H), 8.52 (dd, J₁=1.5 Hz, J₂=5.4 Hz, 2H).

Next, an absorption spectrum of PCCPA was measured at room temperatureusing an ultraviolet-visible spectrophotometer (V-550, manufactured byJASCO Corporation) with the use of a toluene solution. An emissionspectrum of PCCPA was measured at room temperature using a fluorescencespectrophotometer (FS920, manufactured by Hamamatsu PhotonicsCorporation) with the use of a toluene solution. The measurement resultsare shown in FIG. 12. Further, a thin film of PCCPA was similarlymeasured by film formation of PCCPA by an evaporation method. Themeasurement results are shown in FIG. 13. In each of FIG. 12 and FIG.13, the horizontal axis indicates the wavelength (nm) and the verticalaxis indicates the absorption intensity (arbitrary unit) and emissionintensity (arbitrary unit).

According to FIG. 12, in the case of the toluene solution of PCCPA,absorption was observed at wavelengths of around 355 nm, around 375 nm,and around 395 nm. According to FIG. 13, in the case of the thin film ofPCCPA, absorption was observed at wavelengths of around 357 nm, around379 nm, and around 401 nm.

According to FIG. 12 and FIG. 13, the thin film of PCCPA has an emissionpeak at 454 nm (the excitation wavelength: 380 nm), and the toluenesolution thereof has an emission peak at 436 nm (the excitationwavelength: 370 nm). Thus, it is found that PCCPA is suitable for use ina light-emitting element that emits blue light in particular.

The ionizing potential of the thin film of PCCPA was measured using aphotoelectron spectrometer (AC-2, manufactured by Riken Keiki Co., Ltd)in the air and found to be 5.40 eV. As a result, the HOMO level wasfound to be −5.40 eV. Further, an absorption edge was obtained from aTauc plot assuming direct transition by use of the data of theabsorption spectrum of PCCPA in the thin film state, and the absorptionedge was regarded as an optical energy gap. The energy gap was 2.90 eV.A LUMO level of −2.50 eV was obtained from the obtained values of theenergy gap and the HOMO level.

The oxidation-reduction characteristics of PCCPA were measured by cyclicvoltammetry (CV). An electrochemical analyzer (ALS model 600a,manufactured by BAS Inc.) was used for the measurement. Further,dimethylformamide (DMF) and tetra-n-butylammonium perchlorate(n-Bu₄NClO₄) were used as a solvent and a supporting electrolyte,respectively, and the amount thereof adjusted to yield a concentrationof 10 mmol per L of DMF. Furthermore, the amount of PCCPA was adjustedto yield a concentration of 1 mmol per L of the electrolysis solution. Aplatinum electrode (PTE platinum electrode, produced by BAS Inc.), aplatinum electrode (Pt counter electrode (5 cm) for VC-3, produced byBAS Inc.), and an Ag/Ag⁺ electrode (RE5 non-aqueous solvent referenceelectrode, produced by BAS Inc.) were used as a working electrode, anauxiliary electrode, and a reference electrode, respectively. Themeasurement was performed at a scan rate of 0.1 V/s for 100 cycles. FIG.14 shows the measurement result on the oxidation side. FIG. 15 shows themeasurement result on the reduction side. In each of FIG. 14 and FIG.15, the horizontal axis indicates a potential (V) of the workingelectrode with respect to the reference electrode, and the vertical axisindicates a current value (μA) that flowed between the working electrodeand the counter electrode.

FIG. 14 shows that the oxidation potential of PCCPA was 0.47 V (withrespect to Ag/Ag⁺). FIG. 15 shows that the reduction potential of PCCPAwas −2.19 V (with respect to Ag/Ag⁺). Through the measurement for 100cycles of scanning, distinct oxidation peaks and reduction peaks wereobserved in the CV curves. Therefore, it is found that the anthracenederivative of the present invention is a substance in which thereversibility of oxidation-reduction reactions is excellent.

Synthesis Example 2

In Synthesis Example 2, a synthesis method of an anthracene derivative4-{9-[4-(10-phenyl-9-anthryl)phenyl]-9H-carbazol-3-yl}triphenylamine(TPCPA) of the present invention represented by a structural formula(246) is specifically described.

Step 1: Synthesis of 3-bromo-9H-carbazole

32 g (0.19 mmol) of 9H-carbazole was put into a 2 L Erlenmeyer flask,and then ether acetate (1.2 L) was added thereto so that the9H-carbazole was dissolved in the ether acetate. To this solution wasadded 34 g (0.19 mol) of N-bromosuccinimide (NBS), and the mixture wasstirred for about 15 hours in the air at room temperature. After thestirring, water was added to the mixture so that the precipitate wasdissolved in the mixture. The organic layer of this mixture was washedwith water three times and then with a saturated saline solution once.Magnesium sulfate was added so that the organic layer was dried. Afterthe drying, the mixture was subjected to gravity filtration. Theobtained filtrate was condensed to give a white solid. The obtainedsolid was recrystallized with ether acetate/hexane to give 36 g of awhite powdered solid, which was the object of the synthesis, at a yieldof 67%. A synthesis scheme of Step 1 is shown in (c-1) given below.

Step 2: Synthesis of N,N-diphenylanilin-4-boronic acid

10 g (30 mmol) of 4-bromotriphenylamine was put into a 500 mL three-neckflask. The air in the flask was replaced with nitrogen. To the mixturewere added 20 mL of tetrahydrofuran (THF), and then the mixture wasstirred at −80° C. Into this solution, 20 mL (32 mmol) of n-butyllithium(a 1.6 mol/L hexane solution) was dropped by a syringe. After thedropping, this solution was stirred at the same temperature for 1 hour.After the stirring, 40 mL (60 mmol) of trimethyl borate was added to thesolution, and the solution was stirred for 1 hour while the temperatureof the solution was being increased to room temperature. To the solutionwas added 200 mL (1.0 mol/L) of hydrochloric acid, and then the solutionwas stirred for about 15 hours. The organic layer was washed with asaturated sodium hydrogen carbonate solution and then a saturated salinesolution. Then, the organic layer was dried with magnesium sulfate. Thismixture was subjected to gravity filtration. The obtained filtrate wascondensed to give a white solid. The obtained solid was recrystallizedwith chloroform/hexane to give 5.2 g of a white powdered solid, whichwas the object of the synthesis, at a yield of 58%. A synthesis schemeof Step 2 is shown in (c-2) given below.

Step 3: Synthesis of 4-(9H-carbazol-3-yl}triphenylamine (ITC)

2.5 g (10 mmol) of 3-bromo-9H-carbazole, 2.9 g (10 mmol) ofN,N-diphenylanilin-4-boronic acid, and 152 mg (0.50 mmol) oftri(ortho-tolyl)phosphine were put into a 200 mL three-neck flask. Theair in the flask was replaced with nitrogen. To the mixture were added50 mL of ethyleneglycoldimethylether and 10 mL (2.0 mol/L) of an aqueoussolution of potassium carbonate. This mixture was stirred to be degassedwhile the pressure was reduced. After the degassing, 50 mg (0.20 mmol)of palladium(II) acetate was added to the mixture. This mixture wasstirred at 80° C. for 3 hours. After the stirring, this mixture waswashed with water and then a saturated saline solution. After thewashing, magnesium sulfate was added to the organic layer so that theorganic layer was dried. The mixture was subjected to gravityfiltration. The obtained filtrate was condensed to give a solid. Thissolid was purified by silica gel column chromatography (a developingsolvent was a mixed solvent of hexane:toluene=6:4) to give 3.4 g of awhite solid TPC, which was the object of the synthesis, at a yield of82%. A synthesis scheme of Step 3 is shown in (c-3) given below.

The solid obtained in the above Step 3 was analyzed by ¹H NMR. Themeasurement result is described below, and the ¹H NMR chart is shown inFIG. 16. They show that the organic compound TPC of the presentinvention represented by the structural formula (622), which is used inany of the anthracene derivatives of the present invention, was obtainedin this synthesis example.

¹H NMR (DMSO-d₆, 300 MHz): δ=6.99-7.41 (m, 14H), 7.48 (d, J=8.1 Hz, 1H),7.52 (d, J=8.7 Hz, 1H), 7.65-7.71 (m, 3H), 8.18 (d, J=7.8 Hz, 1H), 8.39(d, J=1.5 Hz, 1H), 11.28 (s, 1H).

Step 4: Synthesis of TPCPA

1.2 g (3.0 mmol) of 9-phenyl-10-(4-bromophenyl)anthracene, 1.2 g (3.0mmol) of TPC, and 1.0 g (10 mmol) of sodium tert-butoxide were put intoa 100 mL three-neck flask. The air in the flask was replaced withnitrogen. To the mixture were added 20 mL of toluene and 0.1 mL oftri(tert-butyl)phosphine (a 10 wt % hexane solution). This mixture wasstirred to be degassed while the pressure was reduced. After thedegassing, 50 mg (0.090 mmol) of bis(dibenzylideneacetone)palladium(0)was added the mixture. This mixture was refluxed at 110° C. for 8 hours.After the reflux, about 50 mL of toluene was added to the mixture, andthen the mixture was stirred for about 30 minutes. Then, this mixturewas washed with water and a saturated saline solution in this order.After the washing, the organic layer was dried with magnesium sulfate.This mixture was subjected to gravity filtration. The obtained filtratewas condensed to give an oily substance. The obtained oily substance waspurified by silica gel column chromatography (a developing solvent was amixed solvent of hexane:toluene=1:1) to give a light yellow solid TPCPA.This solid was recrystallized with toluene/hexane to give 1.0 g of alight yellow powdered solid TPCPA, which was the object of thesynthesis, at a yield of 41%. A synthesis scheme of Step 4 is shown in(c-4) given below.

The solid obtained in the above Step 4 was analyzed by ¹H NMR. Themeasurement result is described below, and the ¹H NMR chart is shown inFIG. 17. They show that the anthracene derivative TPCPA of the presentinvention represented by the structural formula (223) was obtained inthis synthesis example.

¹H NMR (CDCl₃, 300 MHz): δ=7.02-7.87 (m, 36H), 8.24 (d, J=7.8 Hz, 1H),8.39 (s, 1H).

Further, the decomposition temperature of TPCPA which is the anthracenederivative of the present invention was measured using a high vacuumdifferential type differential thermal balance (TG-DTA2410SA,manufactured by Bruker AXS K.K.). When the temperature was increased ata rate of 10° C./min under a pressure of 10 Pa, 5% weight reduction wasseen at 330° C., which is indicative of high thermal stability.

Next, an absorption spectrum of TPCPA was measured at room temperatureusing an ultraviolet-visible spectrophotometer (V-550, manufactured byJASCO Corporation) with the use of a toluene solution. An emissionspectrum of TPCPA was measured at room temperature using a fluorescencespectrophotometer (FS920, manufactured by Hamamatsu PhotonicsCorporation) with the use of a toluene solution. The measurement resultsare shown in FIG. 18. Further, a thin film of TPCPA was similarlymeasured by film formation of TPCPA by an evaporation method. Themeasurement results are shown in FIG. 19. In each of FIG. 18 and FIG.19, the horizontal axis indicates the wavelength (nm) and the verticalaxis indicates the absorption intensity (arbitrary unit) and theemission intensity (arbitrary unit).

According to FIG. 18, in the case of the toluene solution of TPCPA,absorption was observed at wavelengths around 374 nm and around 394 nm.According to FIG. 19, in the case of the thin film of TPCPA, absorptionwas observed at wavelengths of around 376 nm and around 402 nm.

According to FIG. 18 and FIG. 19, the thin film of TPCPA has an emissionpeak at 460 nm (the excitation wavelength: 395 nm), and the toluenesolution thereof has an emission peak at 432 nm (the excitationwavelength: 370 nm). Thus, it is found that TPCPA is suitable for use ina light-emitting element that emits blue light in particular.

The ionizing potential of the thin film of TPCPA was measured using aphotoelectron spectrometer (AC-2, manufactured by Riken Keiki Co., Ltd)in the air and found to be 5.28 eV. As a result, the HOMO level wasfound to be −5.28 eV. Further, an absorption edge was obtained from aTauc plot assuming direct transition by use of the data of theabsorption spectrum of TPCPA in the thin film state, and the absorptionedge was regarded as an optical energy gap. The energy gap was 2.93 eV.A LUMO level of −2.35 eV was obtained from the obtained values of theenergy gap and the HOMO level.

The oxidation-reduction characteristics of TPCPA were measured by cyclicvoltammetry (CV). An electrochemical analyzer (ALS model 600a,manufactured by BAS Inc.) was used for the measurement. Further,dimethylformamide (DMF) and tetra-n-butylammonium perchlorate(n-Bu₄NClO₄) were used as a solvent and a supporting electrolyte,respectively, and the amount thereof adjusted to yield a concentrationof 10 mmol per L of DMF. Furthermore, the amount of TPCPA was adjustedto yield a concentration of 1 mmol per L of the electrolysis solution. Aplatinum electrode (PIE platinum electrode, produced by BAS Inc.), aplatinum electrode (Pt counter electrode (5 cm) for VC-3, produced byBAS Inc.), and an Ag/Ag⁺ electrode (RE5 non-aqueous solvent referenceelectrode, produced by BAS Inc.) were used as a working electrode, anauxiliary electrode, and a reference electrode, respectively. Themeasurement was performed at a scan rate of 0.1 V/s for 100 cycles. FIG.20 shows the measurement result on the oxidation side. FIG. 21 shows themeasurement result on the reduction side. In each of FIG. 20 and FIG.21, the horizontal axis indicates a potential (V) of the workingelectrode with respect to the reference electrode, and the vertical axisindicates a current value (μA) that flowed between the working electrodeand the counter electrode.

FIG. 20 shows that the oxidation potential of TPCPA was 0.58 V (withrespect to Ag/Ag⁺). FIG. 21 shows that the reduction potential of TPCPAwas −2.22 V (with respect to Ag/Ag⁺). Through the measurement for 100cycles of scanning, distinct oxidation peaks and reduction peaks wereobserved in the CV curves. Therefore, it is found that the anthracenederivative of the present invention is a substance in which thereversibility of oxidation-reduction reactions is excellent.

Example 2

In Example 2, a light-emitting element of the present invention isdescribed using FIG. 22. Chemical formulae of materials used in thisexample are shown below.

(Light-Emitting Element 1)

First, indium tin oxide containing silicon oxide (ITSO) was deposited bya sputtering method over a glass substrate 2100 to form a firstelectrode 2101. It is to be noted that the film thickness of the firstelectrode was 110 nm, and the area of the electrode was 2 mm×2 mm.

Next, the substrate over which the first electrode was formed was fixedto a substrate holder provided in a vacuum evaporation apparatus, sothat a surface over which the first electrode was formed faced downward.Then, after the pressure of the vacuum evaporation apparatus was reducedto about 10⁻⁴ Pa, a layer 2102 including a composite material, which wasformed of an organic compound and an inorganic compound, was formed overthe first electrode 2101 by co-deposition of NPB and molybdenum(VI)oxide. The film thickness of the layer 2102 was to be 50 μm, and theratio of NPB and molybdenum(VI) oxide was adjusted to be 4:1(=NPB:molybdenum oxide) in weight ratio. It is to be noted that theco-deposition method is an evaporation method in which evaporation iscarried out from a plurality of evaporation sources at the same time inone treatment chamber.

Subsequently, NPB was deposited to a thickness of 10 nm over the layer2102 including a composite material by an evaporation method using theresistance heating system, thereby forming a hole-transporting layer2103.

Further, by co-deposition of PCAPA and PCCPA which is the anthracenederivative of the present invention and was synthesized in SynthesisExample 1 of Example 1, a first layer 2121 was formed to a thickness of30 nm over the hole-transporting layer 2103. The weight ratio of PCCPAand PCAPA was adjusted to 1:0.05 (=PCCPA:PCAPA).

Further, by co-deposition of CzPA and PCAPA, a second layer 2122 wasformed to a thickness of 30 nm over the first layer 2121. The weightratio of CzPA and PCAPA was adjusted to 1:0.05 (=CzPA:PCAPA).

Thereafter, tris(8-quinolinolato)aluminum (Alq) was deposited to a filmthickness of 30 nm over the second layer 2122 by an evaporation methodusing the resistance heating system, thereby an electron-transportinglayer 2104 was formed.

Furthermore, lithium fluoride was deposited to a thickness of 1 nm wasformed over the electron-transporting layer 2104 to form anelectron-injecting layer 2105.

Lastly, aluminum was deposited to a film thickness of 200 nm over theelectron-injecting layer 2105 by the evaporation method using theresistance heating system, a second electrode 2106 was formed.Accordingly, a light-emitting element 1 was fabricated.

Current density-luminance characteristics, voltage-luminancecharacteristics, and luminance-current efficiency characteristics of thelight-emitting element 1 are shown in FIG. 23, FIG. 24, and FIG. 25,respectively. Also, the emission spectrum measured at a current of 1 mAis shown in FIG. 26. A CIE chromaticity coordinate of the light-emittingelement 1 at luminance of 1000 cd/m² was (x=0.17, y=0.29), and lightemission from the light-emitting element 1 was blue.

(Light-Emitting Element 2)

A light-emitting element 2 was fabricated in a similar manner to thelight-emitting element 1 except that TPCPA which is the anthracenederivative of the present invention synthesized in Synthesis Example 2of Example 1 was used instead of PCCPA. In other words, as illustratedin FIG. 22, PCAPA and TPCPA were co-deposited to form a first layer 2121having a thickness of 30 nm over the hole-transporting layer 2103, andthe other layers of the light-emitting element 2 were formed in asimilar manner to the light-emitting element 1. The weight ratio ofTPCPA and PCAPA was adjusted to 1:0.05 (=TPCPA:PCAPA).

Current density-luminance characteristics, voltage-luminancecharacteristics, and luminance-current efficiency characteristics of thelight-emitting element 2 are shown in FIG. 27, FIG. 28, and FIG. 29,respectively. Also, the emission spectrum measured at a current of 1 mAis shown in FIG. 30. A CIE chromaticity coordinate of the light-emittingelement 2 at luminance of about 1000 cd/m² was (x=0.15, y=0.22), andlight emission from the light-emitting element 2 was blue.

Comparative Example 1

In Comparative Example 1, a comparative element 1 was fabricated in asimilar manner to the light-emitting elements 1 and 2 except that thefirst layer 2121 in FIG. 22 was not formed.

Current density-luminance characteristics, voltage-luminancecharacteristics, and luminance-current efficiency characteristics of thecomparative element 1 are shown in FIG. 31, FIG. 32, and FIG. 33,respectively. Also, the emission spectrum measured at a current of 1 mAis shown in FIG. 34. A CIE, chromaticity coordinate of the comparativeelement 1 at luminance of 1000 cd/m² was (x=0.16, y=0.21), and lightemission from the comparative element 1 was blue.

FIG. 35 shows the results of luminances of the light-emitting element 1,the light-emitting element 2, and the comparative element 1, which weremeasured under the conditions that the initial luminance of each elementwas set 1000 cd/m² and each element was operated at a constant currentdensity.

The current efficiency and life of each light-emitting element wascompared using the above measurement results. The result is shown inTable 1 given below.

TABLE 1 current efficiency (cd/A) life (time) light-emitting element 18.1 440 light-emitting element 2 6.1 52 comparative element 1 4.0 38

In Table 1, “current efficiency” refers to the current efficiencymeasured at luminance of 1000 cd/m² and “life” refers to time that isneeded to reduce an initial luminance of 1000 cd/m² to 90 percent. Thelight-emitting element 1 drastically improved in the current efficiencyand the life compared to the comparative element 1. Further, thelight-emitting element 2 improved in the current efficiency and the lifecompared to the comparative element 1.

As described above, the light-emitting elements of the present inventionexhibited extremely favorable characteristics. Since the anthracenederivative of the present invention is a substance in which thereversibility of oxidation-reduction reactions is excellent, thelight-emitting element of the present shows little luminance decay overan emission time and has a long element life.

Example 3

In Example 3, a light-emitting element of the present invention isdescribed using FIG. 22. Chemical formulae of materials used in thisexample are shown below.

(Light-Emitting Element 3)

A light-emitting element 3 in Example 3 was fabricated in a similarmanner to the light-emitting element 1 of Example 2 except that YGA2Swas used instead of PCAPA in the first layer and YGA2S was used insteadof PCAPA in the second layer. In other words, as illustrated in FIG. 22,PCCPA and YGA2S were co-deposited to form a first layer 2121 having athickness of 30 nm over the hole-transporting layer 2103, CzPA and YGA2Swere co-deposited to form a second layer 2121 having a thickness of 30nm over the first layer 2121, and the other layers of the light-emittingelement 3 were formed in a similar manner to the light-emitting element1. The weight ratio of PCCPA and YGA2S was adjusted to 1:0.05(=PCCPA:YGA2S), and that of CzPA and YGA2S was adjusted to 1:0.05(=CzPA:YGA2S).

Current density-luminance characteristics, voltage-luminancecharacteristics, and luminance-current efficiency characteristics of thelight-emitting element 3 are shown in FIG. 36, FIG. 37, and FIG. 38,respectively. Also, the emission spectrum measured at a current of 1 mAis shown in FIG. 39. A CIE chromaticity coordinate of the light-emittingelement 3 at luminance of about 1000 cd/m² was (x=0.17, y=0.19), andlight emission from the light-emitting element 3 was blue.

A light-emitting element 4 fabricated in Example 3 is a light-emittingelement that uses the anthracene derivative TPCPA of the presentinvention. The light-emitting element 4 is specifically described.

(Light-Emitting Element 4)

A light-emitting element 4 was fabricated in a similar manner to thelight-emitting element 3 except that TPCPA was used instead of PCCPA. Inother words, as illustrated in FIG. 22, YGA2S and TPCPA which isrepresented by a structural formula (223) were co-deposited to form afirst layer 2121 having a thickness of 30 nm over the hole-transportinglayer 2103, and the other layers of the light-emitting element 4 wereformed in a similar manner to the light-emitting element 3. The weightratio of TPCPA and YGA2S was adjusted to 1:0.05 (=TPCPA:YGA2S).

Current density-luminance characteristics, voltage-luminancecharacteristics, and luminance-current efficiency characteristics of thelight-emitting element 4 are shown in FIG. 40, FIG. 41, and FIG. 42,respectively. Also, the emission spectrum measured at a current of 1 mAis shown in FIG. 43. A CIE chromaticity coordinate of the light-emittingelement 4 at luminance of 1000 cd/m² was (x=0.16, y=0.17), and lightemission from the light-emitting element 4 was blue.

Comparative Example 2

In Comparative Example 2, a comparative element 2 was fabricated in asimilar manner to the light-emitting elements 3 and 4 except that thefirst layer 2121 in FIG. 22 was not formed.

Current density-luminance characteristics, voltage-luminancecharacteristics, and luminance-current efficiency characteristics of thecomparative element 2 are shown in FIG. 44, FIG. 45, and FIG. 46,respectively. Also, the emission spectrum measured at a current of 1 mAis shown in FIG. 47. A CIE chromaticity coordinate of the comparativeelement 2 at luminance of 1000 cd/m² was (x=0.16, y=0.17), and lightemission from the comparative element 2 was blue.

The current efficiencies at a luminance of 1000 cd/m² of thelight-emitting element 3, the light-emitting element 4, and thecomparative element 2 were compared. The current efficiencies of thelight-emitting element 3, the light-emitting element 4, and thecomparative element 2 were, respectively, 5.0 cd/A, 5.2 cd/A, and 3.9cd/A. Thus, it is found that the light-emitting element having highemission efficiency can be realized according to the present invention.

Example 4 Synthesis Example 3

In Synthesis Example 3, a synthesis method of an anthracene derivative9,9″-diphenyl-9′-[4-(10-phenyl-9-anthryl)phenyl]-3,3′:6′,3″-ter(9H-carbazole) (PC2CPA) of the present invention represented by a structuralformula (193) is specifically described.

Step 1: Synthesis of 9-phenyl-9H-carbazol-3-boronic acid

10 g (32 mmol) of 3-bromo-9-phenyl-9H-carbazole was put into a 500 mLthree-neck flask. The air in the flask was replaced with nitrogen. Tothe mixture were added 150 mL of tetrahydrofuran (THF), and then thesolution was cooled to −80° C. Into this solution, 22 mL (36 mmol) ofn-butyllithium (a 1.61 mol/L hexane solution) was dropped by a syringe.After the dropping was completed, this solution was stirred at the sametemperature for 1 hour. After the stirring, 4.6 mL, (40 mmol) oftrimethyl borate was added to the solution, and the solution was stirredfor about 15 hours while the temperature of the solution was beingincreased to room temperature. Thereafter, to the solution was addedabout 50 mL (1.0 mol/L) of dilute hydrochloric acid, and then thesolution was stirred for 1 hour. After the stirring, the aqueous layerof the mixture was extracted with ether acetate. The extract wascombined with the organic layer and then washed with a saturated sodiumhydrogen carbonate solution. The organic layer was dried with magnesiumsulfate. After the drying, this mixture was subjected to gravityfiltration. The obtained filtrate was condensed to give an oily lightbrown substance. The obtained oily substance was recrystallized withchloroform/hexane to give 6.2 g of a light brown powder, which was theobject of the synthesis, at a yield of 68%. A synthesis scheme of Step 1is shown in (d-1) given below.

Step 2: Synthesis of 9,9″-diphenyl-3,3′:6′,3″-ter(9H-carbazole) (PC2C)

1.0 g (3.1 mmol) of 3,6-dibromocarbazole, 1.8 g (6.2 mmol) ofN-phenyl-9H-carbazol-3-boronic acid, and 457 mg (1.5 mmol) oftris(ortho-tolyl)phosphine were put into a 300 mL three-neck flask. Tothe mixture were added 20 mL of ethanol, 50 mL of toluene, and 20 mL(2.0 mol/L) of an aqueous solution of potassium carbonate. This mixturewas stirred to be degassed while the pressure was reduced. To thismixture was added 70 mg (0.30 mmol) of palladium(II) acetate. Thismixture was refluxed at 110° C. for 5 hours. After a predetermined timepassed, the aqueous layer was extracted with toluene. The extract wascombined with the organic layer and then washed with water and furtherwith a saturated saline solution. The organic layer was dried withmagnesium sulfate. This mixture was subjected to gravity filtration. Theobtained filtrate was condensed to give an oily brown substance. Theobtained oily substance was purified by silica gel column chromatography(a developing solvent was a mixed solvent of hexane ether acetate=3:1)to give a white solid. This solid was recrystallized withchloroform/hexane to give 1.2 g of a white powder, which was the objectof the synthesis, at a yield of 60%. A synthesis scheme of Step 2 isshown in (d-2) given below.

The obtained compound was analyzed by nuclear magnetic resonance (NMR)measurement, whereby it is confirmed that the compound is PC2C which isan organic compound of the present invention represented by a structuralformula (568).

Hereinafter, the ¹H NMR data is shown. ¹H NMR (CDCl₃, 300 MHz):δ=7.43-7.62 (m, 20H), 7.78-7.83 (m, 4H), 8.11 (s, 1H), 8.24 (d, J=7.8Hz, 2H), 8.49 (dd, J₁=1.5 Hz, J₂=4.8 Hz, 4H). The ¹H NMR charts areshown in FIGS. 48A and 48B. The range of 6.5 ppm to 9.0 ppm in FIG. 48Ais expanded and shown in FIG. 48B.

Step 3: Synthesis of9,9″-diphenyl-9′-[4-(10-phenyl-9-anthryl)phenyl]-3,3′:6″,3″-ter(9H-carbazole)(PC2CPA)

0.63 g (1.5 mmol) of 9-(4-bromophenyl)-10-phenylanthracene, 1.0 g (1.5mmol) of 9,9″-diphenyl-3,3′:6′,3″-ter(9H-carbazole) (PC2C), and 0.50 g(4.5 mmol) of sodium tert-butoxide were put into a 200 mL three-neckflask. The air in the flask was replaced with nitrogen. To the mixturewere added 20 mL of toluene and 0.10 mL of tri(tert-butyl)phosphine (a10 wt % hexane solution). This mixture was stirred to be degassed whilethe pressure was reduced. After the degassing, 43 mg of (0.075 mmol)bis(dibenzylideneacetone)palladium(0) of was added to the mixture. Thismixture was stirred at 110° C. for 2 hours under a stream of nitrogen.After the stirring, the mixture was subjected to suction filtrationthrough celite (produced by Wako Pure Chemical Industries, Ltd., CatalogNo. 531-16855), alumina, and Florisil (produced by Wako Pure ChemicalIndustries, Ltd., Catalog No. 540-00135). The obtained filtrate wascondensed to give a solid. The solid was purified by silica gel columnchromatography (a developing solvent was a mixed solvent ofhexane:toluene=3:1) to give a light yellow solid. This solid wasrecrystallized with toluene/hexane to give 0.69 g of a light yellowpowder, which was the object of the synthesis, at a yield of 47%. Asynthesis scheme of Step 3 is shown in (d-3) given below.

The obtained compound was analyzed by nuclear magnetic resonance (NMR)measurement, whereby it is confirmed that the compound is9,9″-diphenyl-9′-[4-(10-phenyl-9-anthryl)phenyl]-3,3′:6′,3″-ter(9H-carbazole)(PC2CPA).

Hereinafter, the ¹H NMR data is shown. ¹H NMR (CDCl₃, 300 MHz):δ=7.30-7.70 (m, 27H), 7.75-7.96 (m, 14H), 8.28 (d, J=7.8 Hz, 2H), 8.54(d, J=1.5 Hz, 2H), 8.63 (d, J=1.5 Hz, 2H). The ¹H NMR charts are shownin FIGS. 49A and 49B. The range of 7.0 ppm to 9.0 ppm in FIG. 49A isexpanded and shown in FIG. 49B.

Next, an absorption spectrum of PC2CPA was measured at room temperatureusing an ultraviolet-visible spectrophotometer (V-550, manufactured byJASCO Corporation) with the use of a toluene solution. The measurementresult is shown in FIG. 50. In FIG. 50, the horizontal axis indicatesthe wavelength (nm) and the vertical axis indicates the absorptionintensity (arbitrary unit). An emission spectrum of PC2CPA was measuredat room temperature using a fluorescence spectrophotometer (FS920,manufactured by Hamamatsu Photonics Corporation) with the use of atoluene solution. The measurement result is shown in FIG. 51. In FIG.51, the horizontal axis indicates the wavelength (nm) and the verticalaxis indicates the emission intensity (arbitrary unit).

Further, a thin film of PC2CPA was similarly measured by film formationof PC2CPA by an evaporation method. The absorption spectrum and theemission spectrum are shown in FIG. 52 and FIG. 53, respectively. Ineach of FIG. 52 and FIG. 53, the horizontal axis indicates thewavelength (nm) and the vertical axis indicates the absorption intensity(arbitrary unit) and emission intensity (arbitrary unit).

According to FIG. 50, in the case of the toluene solution of PC2CPA,absorption was observed at wavelengths of around 307 nm, around 354 nm,around 376 nm, and around 397 nm. According to FIG. 52, in the case ofthe thin film of PC2CPA, absorption was observed at wavelengths ofaround 262 nm, around 313 nm, around 381 nm, and around 403 nm.

According to FIG. 51, the toluene solution of PC2CPA has an emissionpeak at 422 nm (the excitation wavelength: 397 nm). According to FIG.53, the thin film thereof has an emission peak at 457 nm (the excitationwavelength: 398 nm). Thus, it is found that PC2CPA is suitable for usein a light-emitting element that emits blue light in particular.

Synthesis Example 4

In Synthesis Example 4, a synthesis method of an anthracene derivative4,4′-{9-[4-(10-phenyl-9-anthryl)phenyl]-9H-carbazol-3,6-diyl}bis(N,N-diphenylaniline)(TP2CPA) of the present invention represented by a structural formula(312) is specifically described.

Step 1: Synthesis of 4,4′-(9H-carbazol-3,6-diyl)bis(N,N-diphenylaniline)(TP2C)

1.1 g (3.5 mmol) of 3,6-dibromocarbazole, 2.0 g (7.0 mmol) oftriphenylamine-4-boronic acid, and 0.24 g (1.1 mmol) oftri(ortho-tolyl)phosphine were put into a 300 mL three-neck flask. Tothe mixture were added 30 mL of ethanol, 50 mL of toluene, and 10 mL(2.0 mol/L) of an aqueous solution of potassium carbonate. This mixturewas stirred to be degassed while the pressure was reduced. After thedegassing, 47 mg (0.21 mmol) of palladium(II) acetate was added to themixture. This mixture was stirred at 80° C. for 3 hours under a streamof nitrogen. After the stirring, the aqueous layer of the mixture wasextracted with toluene. The extract was combined with the organic layerand then washed with a saturated saline solution. Then, the obtainedorganic layer was dried with magnesium sulfate. After the drying, themixture was subjected to gravity filtration. The obtained filtrate wascondensed to give an oily light yellow substance. The obtained oilysubstance was purified by silica gel column chromatography (a developingsolvent was a mixed solvent of toluene:hexane=1:1) to give an oily lightyellow substance. This oily substance was recrystallized withtoluene/hexane to give 1.2 g of a white powder, which was the object ofthe synthesis, at a yield of 51%. A synthesis scheme of Step 1 is shownin (e-1) given below.

The obtained compound was analyzed by nuclear magnetic resonance (NMR)measurement, whereby it is continued that the compound is TP2C which isan organic compound of the present invention represented by a structuralformula (692).

Hereinafter, the ¹H NMR data is shown. ¹H NMR (DMSO-d₆, 300 MHz):δ=7.03-7.11 (m, 16H), 7.30-7.35 (m, 8H), 7.53-7.55 (m, 2H), 7.68-7.73(m, 6H), 8.52 (s, 2H), 11.3 (s, 1H). The ¹H NMR charts are shown inFIGS. 54A and 54B. The range of 6.5 ppm to 9.0 ppm in FIG. 54A isexpanded and shown in FIG. 54B.

Step 2: Synthesis of4,4′-{9-[4-(10-phenyl-9-anthryl)phenyl]-9H-carbazol-3,6-diyl}bis(N,N-diphenylaniline)(TP2CPA)

0.70 g (1.7 mmol) of 9-(4-bromophenyl)-10-phenylanthracene, 1.1 g (1.7mmol) of 4,4′-(9H-carbazol-3,6-diyl)bis(N,N-diphenylaniline) (TP2C), and0.49 g (9.0 mmol) of sodium tert-butoxide were put into a 100 mLthree-neck flask. The air in the flask was replaced with nitrogen. Then,to the mixture were added 30 mL of toluene and 0.20 mL oftri(tert-butyl)phosphine (a 10 wt % hexane solution). This mixture wasstirred to be degassed while the pressure was reduced. After thedegassing, 46 mg (0.080 mmol) of bis(dibenzylideneacetone)palladium(0)was added to the mixture. This mixture was stirred at 110° C. for 3hours under a stream of nitrogen. After the stirring, the mixture wassubjected to suction filtration through celite (produced by Wako PureChemical Industries, Ltd., Catalog No. 531-16855), alumina, and Florisil(produced by Wako Pure Chemical Industries, Ltd., Catalog No.540-00135). The obtained filtrate was condensed to give a light yellowsolid. This solid was recrystallized with toluene/hexane to give 0.70 gof a light yellow powder, which was the object of the synthesis, at ayield of 42%. A synthesis scheme of Step 2 is shown in (e-2) givenbelow.

The obtained compound was analyzed by nuclear magnetic resonance (NMR)measurement, whereby it is confirmed that the compound is4,4′-{9-[4-(10-phenyl-9-anthryl)phenyl]-9H-carbazol-3,6-diyl}bis(N,N-diphenylaniline)(TP2CPA).

Hereinafter, the ¹H NMR data is shown. ¹H NMR (DMSO-d₆, 300 MHz):δ=7.04-7.16 (m, 17H), 7.30-7.36 (m, 8H), 7.49-7.51 (m, 5H), 7.65-7.85(m, 17H), 7.93-7.95 (m, 2H), 8.65 (s, 2H). The ¹H NMR charts are shownin FIGS. 55A and 55B. The range of 6.5 ppm to 9.0 ppm in FIG. 55A isexpanded and shown in FIG. 55B.

Next, an absorption spectrum of TP2CPA was measured at room temperatureusing an ultraviolet-visible spectrophotometer (V-550, manufactured byJASCO Corporation) with the use of a toluene solution. The measurementresult is shown in FIG. 56. In FIG. 56, the horizontal axis indicatesthe wavelength (nm) and the vertical axis indicates the absorptionintensity (arbitrary unit). An emission spectrum of TP2CPA was measuredat room temperature using a fluorescence spectrophotometer (FS920,manufactured by Hamamatsu Photonics Corporation) with the use of atoluene solution. The measurement result is shown in FIG. 57. In FIG.57, the horizontal axis indicates the wavelength (nm) and the verticalaxis indicates the emission intensity (arbitrary unit).

Further, a thin film of TP2CPA was similarly measured by film formationof TP2CPA by an evaporation method. The absorption spectrum and emissionspectrum are shown in FIG. 58 and FIG. 59, respectively. In each of FIG.58 and FIG. 59, the horizontal axis indicates the wavelength (nm) andthe vertical axis indicates the absorption intensity (arbitrary unit)and emission intensity (arbitrary unit).

According to FIG. 56, in the case of the toluene solution of TP2CPA,absorption was observed at wavelengths of around 329 nm, around 374 nm,and around 396 nm. According to FIG. 58, in the case of the thin film ofTP2CPA, absorption was observed at wavelengths of around 264 nm, around331 nm, and around 401 nm.

According to FIG. 57, the toluene solution of TP2CPA has an emissionpeak at 431 nm (the excitation wavelength: 341 nm). According to FIG.59, the thin film thereof has emission peaks at 459 nm and 546 nm (theexcitation wavelength: 400 nm). Thus, it is found that TP2CPA issuitable for use in a light-emitting element that emits blue light inparticular.

Synthesis Example 5

In Synthesis Example 5, a synthesis method of an anthracene derivative3-[4-(9H-carbazol-9-yl)phenyl]-9-[4-(10-phenyl-9-anthryl)phenyl]-9H-carbazole(CPCPA) of the present invention represented by a structural formula(343) is specifically described.

Step 1: Synthesis of 9-(4-bromophenyl)-9H-carbazole

56 g (240 mmol) of p-dibromobenzene, 31 g (180 mmol) of 9H-carbazole,4.6 g (24 mmol) of copper(I) iodide, 66 g (480 mmol) of potassiumcarbonate, and 2.1 g (8 mmol) of 18-crown-6-ether were put into a 300 mLthree-neck flask. The mixture was heated at about 100° C., and then 8 mLof N,N′-dimethylpropyleneurea (DMPU) was added thereto. This mixture wasstirred at 180° C. for 6 hours. After the stirring, the mixture wascooled to 100° C. To the mixture was added about 200 mL of toluene, andthen the mixture was cooled to room temperature. After the cooling, thismixture was subjected to suction filtration so that the precipitate wasremoved. The obtained filtrate was washed with dilute hydrochloric acid,a saturated sodium hydrogen carbonate solution, and a saturated salinesolution in this order. The organic layer was dried with magnesiumsulfate. Then, the mixture was subjected to gravity filtration. Theobtained filtrate was condensed to give an oily substance. This oilysubstance was purified by silica gel column chromatography (a developingsolvent was a mixed solvent of hexane:ether acetate=9:1), and thenrecrystallized with chloroform/hexane to give 21 g of a light brownplate-like crystal, which was the object of the synthesis, at a yield of35%. A synthesis scheme of Step 1 is shown in (f-1) given below.

Step 2: Synthesis of 4-(9H-carbazol-9-yl)phenylboronic acid

21.8 g (67.5 mmol) of 9-(4-bromophenyl)-9H-carbazole was put into a 500mL three-neck flask. The air in the flask was replaced with nitrogen. Tothe mixture were added 200 mL of tetrahydrofuran (THF), and then thesolution was cooled to −78° C. Into this solution, 48.9 mL (74.3 mmol)of n-butyllithium (a 1.52 mol/L hexane solution) was dropped, and thesolution was stirred at the same temperature for 2 hours. After thestirring, 17.4 mL (155 mmol) of trimethyl borate was added to thesolution, and the solution was stirred for about 1 hour at the sametemperature. Then, the mixture was stirred for 24 hours while thetemperature of the solution was being increased to room temperature.Thereafter, to the solution was added about 200 mL (1.0 mol/L) ofhydrochloric acid, and then the solution was stirred at room temperaturefor 1 hour. The organic layer of the mixture was washed with water, andthen the aqueous layer was extracted with acetate ether. The extract wascombined with the organic layer and then washed with a saturated salinesolution. The organic layer was dried with magnesium sulfate. After thedrying, the mixture was subjected to suction filtration, and then theobtained filtrate was condensed. The obtained residue was recrystallizedwith chloroform/hexane to give 12.8 g of a white powdered solid, whichwas the object of the synthesis, at a yield of 65.9%. A synthesis schemeof Step 2 is shown in (f-2) given below.

Step 3: Synthesis of 3-[4-(9H-carbazol-9-yl)phenyl]-9H-carbazole (CPC)

5.0 g (20 mmol) of 3-bromo-9H-carbazole, 5.8 g (20 mmol) of4-(9H-carbazol-9-yl)phenylboronic acid, and 308 mg (1.0 mmol) oftri(ortho-tolyl)phosphine were put into a 300 mL three-neck flask. Theair in the flask was replaced with nitrogen. To the mixture were added100 mL of ethyleneglycoldimethylether and 20 mL of an aqueous solutionof potassium carbonate (2.0 mol/L). This mixture was stirred to bedegassed under reduced pressure. After the degassing, 46 mg (0.20 mmol)of palladium(II) acetate was added the mixture. This mixture wasrefluxed at 90° C. for 4.5 hours. After the reflux, the organic layer ofthe mixture was washed with water twice, and the aqueous layer wasextracted with acetate ether. The extract was combined with the organiclayer and then washed with a saturated saline solution. The obtainedorganic layer was dried with magnesium sulfate. After the drying, themixture was subjected to gravity filtration. The obtained filtrate wascondensed to give an oily light brown substance. The obtained oilysubstance was purified by silica gel column chromatography (a developingsolvent was a mixed solvent of hexane:toluene=1:1) to give 5.4 g of awhite powdered solid, which was the object of the synthesis, at a yieldof 65%. A synthesis scheme of Step 3 is shown in (f-3) given below.

The obtained compound was analyzed by nuclear magnetic resonance (NMR)measurement, whereby it is confirmed that the compound is CPC which isan organic compound of the present invention represented by a structuralformula (723).

Hereinafter, the ¹H NMR data is shown. ¹H NMR (CDCl₃, 300 MHz):δ=7.27-7.33 (m, 3H), 7.14-7.58 (m, 8H), 7.67 (d, J=8.1 Hz, 2H), 7.77(dd, J₁=1.7 Hz, J₂=8.6 Hz, 1H), 7.94 (d, J=8.4 Hz, 2H), 8.16-8.18 (m,3H), 8.40 (d, J=12.1 Hz, 1H). The ¹H NMR charts are shown in FIGS. 60Aand 60B. The range of 7.0 ppm to 9.0 ppm in FIG. 60A is expanded andshown in FIG. 60B.

Step 4: Synthesis of3-[4-(9H-carbazol-9-yl)phenyl]-9-[4-(10-phenyl-9-anthryl)phenyl]-9H-carbazole(CPCPA)

1.8 g (4.5 mmol) of 9-(4-bromophenyl)-10-phenylanthracene, 1.8 g (4.5mmol) of 3-[4-(9H-carbazol-9-yl)phenyl]-9H-carbazole (CPC), and 1.1 g(10 mmol) of sodium tert-butoxide were put into a 200 mL three-neckflask. The air in the flask was replaced with nitrogen. To the mixturewere added 25 mL of toluene and 0.10 mL of tri(tert-butyl)phosphine (a10 wt % hexane solution). This mixture was stirred to be degassed whilethe pressure was reduced. After the degassing, 58 mg (0.10 mmol) ofbis(dibenzylideneacetone)palladium(0) was added to the mixture. Thismixture was refluxed and then cooled to room temperature. Then, to themixture was added about 50 mL of toluene. The mixture was subjected tosuction filtration through Florisil (produced by Wako Pure ChemicalIndustries, Ltd., Catalog No. 540-00135), celite (produced by Wako PureChemical Industries, Ltd., Catalog No. 531-16855), and alumina. Theobtained filtrate was condensed to give a light yellow solid. This solidwas recrystallized with toluene/hexane to give 2.6 g of a light yellowpowdered solid, which was the object of the synthesis, at a yield of81%. A synthesis scheme of Step 4 is shown in (f-4) given below.

The obtained compound was analyzed by nuclear magnetic resonance (NMR)measurement, whereby it is confirmed that the compound is3-[4-(9H-carbazol-9-yl)phenyl]-9-[4-(10-phenyl-9-anthryl)phenyl]-9H-carbazole(CPCPA) which is an anthracene derivative of the present invention.

Hereinafter, the ¹H NMR data is shown. ¹H NMR (CDCl₃, 300 MHz):δ=7.30-7.91 (m, 30H), 8.00 (d, J=8.7 Hz, 2H), 8.19 (d, J=7.8 Hz, 2H),8.30 (d, J=7.5 Hz, 1H), 8.53 (d, J=1.2 Hz, 1H). The ¹H NMR charts areshown in FIGS. 61A and 61B. The range of 7.0 ppm to 9.0 ppm in FIG. 61Ais expanded and shown in FIG. 61B.

Next, an absorption spectrum of CPCPA was measured at room temperatureusing an ultraviolet-visible spectrophotometer (V-550, manufactured byJASCO Corporation) with the use of a toluene solution. The measurementresult is shown in FIG. 62. In FIG. 62, the horizontal axis indicatesthe wavelength (nm) and the vertical axis indicates the absorptionintensity (arbitrary unit). An emission spectrum of CPCPA was measuredat room temperature using a fluorescence spectrophotometer (FS920,manufactured by Hamamatsu Photonics Corporation) with the use of atoluene solution. The measurement result is shown in FIG. 63. In FIG.63, the horizontal axis indicates the wavelength (nm) and the verticalaxis indicates the emission intensity (arbitrary unit).

Further, a thin film of CPCPA was similarly measured by film formationof CPCPA by an evaporation method. The absorption spectrum and emissionspectrum are shown in FIG. 64 and FIG. 65, respectively. In each of FIG.64 and FIG. 65, the horizontal axis indicates the wavelength (nm) andthe vertical axis indicates the absorption intensity (arbitrary unit)and emission intensity (arbitrary unit).

According to FIG. 62, in the case of the toluene solution of CPCPA,absorption was observed at wavelengths of around 351 nm, around 373 nm,around and around 394 nm. According to FIG. 64, in the case of the thinfilm of CPCPA, absorption was observed at wavelengths of around 265 nm,around 298 nm, around 382 nm, and around 403 nm.

According to FIG. 63, the toluene solution of CPCPA has an emission peakat 424 nm (the excitation wavelength: 370 nm). According to FIG. 65, thethin film thereof has an emission peak at 440 nm (the excitationwavelength: 401 nm). Thus, it is found that CPCPA is suitable for use ina light-emitting element that emits blue light in particular.

The ionizing potential of the thin film of CPCPA was measured using aphotoelectron spectrometer (AC-2, manufactured by Riken Keiki Co., Ltd)in the air and found to be 5.68 eV. As a result, the HOMO level wasfound to be −5.68 eV. Further, an absorption edge was obtained from aTauc plot assuming direct transition by use of the data of theabsorption spectrum of CPCPA in the thin film state, and the absorptionedge was regarded as an optical energy gap. The energy gap was 2.91 eV.A LUMO level of −2.77 eV was obtained from the obtained values of theenergy gap and the HOMO level.

Synthesis Example 6

In Synthesis Example 6, a synthesis method of an anthracene derivative3-6-bis[4-(9H-carbazol-9-yl)phenyl]-9-[4-(10-phenyl-9-anthryl)phenyl]-9H-carbazole(CP2CPA) of the present invention represented by a structural formula(388) is specifically described.

Step 1: Synthesis of 3-6-bis[4-(9H-carbazol-9-yl)phenyl]-9H-carbazole(CP2C)

1.0 g (3.1 mmol) of 3,6-dibromo-9H-carbazole, 1.8 g (6.2 mmol) of4-(9H-carbazol-9-yl)phenylboronic acid, and 457 mg (1.5 mmol) oftri(ortho-tolyl)phosphine were put into a 300 mL three-neck flask. Tothe mixture were added 20 mL of ethanol, 50 mL of toluene, and 20 mL(2.0 mol/L) of an aqueous solution of potassium carbonate. This mixturewas stirred to be degassed while the pressure was reduced. To themixture was added 70 mg (0.30 mmol) of palladium(II) acetate. Thismixture was refluxed at 110° C. for 5 hours, cooled to room temperature,and then left for 15 hours; accordingly a black solid was precipitated.The precipitated solid was subjected to suction filtration and thencollected. The collected solid was dissolved in toluene which washeated, and this solution was subjected to filtration through celite(produced by Wako Pure Chemical Industries, Ltd., Catalog No.531-16855), alumina, and Florisil (produced by Wako Pure ChemicalIndustries, Ltd., Catalog No. 540-00135). The obtained filtrate wascondensed to give a white solid. The obtained solid was recrystallizedwith toluene/hexane to give 1.1 g of a white powder, which was theobject of the synthesis, at a yield of 58%. A synthesis scheme of Step 1is shown in (g-1) given below.

The obtained compound was analyzed by nuclear magnetic resonance (NMR)measurement, whereby it is confirmed that the compound is CP2C which isan organic compound of the present invention represented by a structuralformula (769).

Hereinafter, the ¹H NMR data is shown. ¹H NMR (CDCl₃, 300 MHz):δ=7.29-7.34 (m, 4H), 7.42-7.53 (m, 8H), 7.60 (d, J=8.7 Hz, 2H), 7.68(dd, J₁=1.5 Hz, J₂=6.0 Hz, 4H), 7.82 (dd, J₁=1.5 Hz, J₂=8.7 Hz, 2H),7.96 (dd, J₁=1.8 Hz, J₂=6.3 Hz, 4H), 8.18 (d, J=7.2 Hz, 4H), 8.24 (s,1H), 8.49 (d, J=1.5 Hz, 2H). The ¹H NMR charts are shown in FIGS. 66Aand 66B. The range of 6.5 ppm to 9.0 ppm in FIG. 66A is expanded andshown in FIG. 66B.

Step 2: Synthesis of3-6-bis[4-(9H-carbazol-9-yl)phenyl]-9-[4-(10-phenyl-9-anthryl)phenyl]-9H-carbazole(CP2CPA)

0.63 g (1.5 mmol) of 9-(4-bromophenyl)-10-phenylanthracene, 1.0 g (1.5mmol) of 3,6-bis[4-(9H-carbazol-9-yl)phenyl]-9H-carbazole (CP2C), and(0.50 g (4.5 mmol) of sodium tert-butoxide were put into a 200 mLthree-neck flask. The air in the flask was replaced with nitrogen. Tothe mixture were added 20 mL of toluene and 0.10 mL oftri(tert-butyl)phosphine (a 10 wt % hexane solution). This mixture wasstirred to be degassed while the pressure was reduced. After thedegassing, 43 mg (0.075 mmol) of bis(dibenzylideneacetone)palladium(0)was added to the mixture. This mixture was stirred at 110° C. for 2hours under a stream of nitrogen, cooled to room temperature, and thenleft for 15 hours; accordingly, a brown solid was precipitated. Theprecipitated solid was subjected to suction filtration and thencollected. The collected solid was dissolved in 200 mL of toluene whichwas heated, and this mixture was subjected to filtration through celite(produced by Wako Pure Chemical Industries, Ltd., Catalog No.531-16855), alumina, and Florisil (produced by Wako Pure ChemicalIndustries, Ltd., Catalog No. 540-00135). The obtained filtrate wascondensed to give a white solid. The obtained solid was recrystallizedwith toluene/hexane to give 1.0 g of a white powder, which was theobject of the synthesis, at a yield of 67%. A synthesis scheme of Step 2is shown in (g-2) given below.

The obtained compound was analyzed by nuclear magnetic resonance (NMR)measurement, whereby it is confirmed that the compound is3,6-bis[4-(9H-carbazol-9-yl)phenyl]-9-[4-(10-phenyl-9-anthryl)phenyl]-9H-carbazole(CP2CPA) which is an anthracene derivative of the present invention.

Hereinafter, the ¹H NMR data is shown. ¹H NMR (CDCl₃, 300 MHz):δ=7.30-7.96 (m, 37H), 8.02 (d, J=8.7 Hz, 4H), 8.18 (d, J=7.2 Hz, 4H),8.62 (d, J=1.5 Hz, 2H). The ¹H NMR charts are shown in FIGS. 67A and67B. The range of 7.0 ppm to 9.0 ppm in FIG. 67A is expanded and shownin FIG. 67B.

Next, an absorption spectrum of CP2CPA was measured at room temperatureusing an ultraviolet-visible spectrophotometer (V-550, manufactured byJASCO Corporation) with the use of a toluene solution. The measurementresult is shown in FIG. 68. In FIG. 68, the horizontal axis indicatesthe wavelength (nm) and the vertical axis indicates the absorptionintensity (arbitrary unit). An emission spectrum of CP2CPA was measuredat room temperature using a fluorescence spectrophotometer (FS920,manufactured by Hamamatsu Photonics Corporation) with the use of atoluene solution. The measurement result is shown in FIG. 69. In FIG.69, the horizontal axis indicates the wavelength (nm) and the verticalaxis indicates the emission intensity (arbitrary unit).

Further, a thin film of CP2CPA was similarly measured by film formationof CP2CPA by an evaporation method. The absorption spectrum and emissionspectrum are shown in FIG. 70 and FIG. 71, respectively. In each of FIG.70 and FIG. 71, the horizontal axis indicates the wavelength (nm) andthe vertical axis indicates the absorption intensity (arbitrary unit)and the emission intensity (arbitrary unit).

According to FIG. 68, in the case of the toluene solution of CP2CPA,absorption was observed at wavelengths of around 294 nm, around 312 nm,around 376 nm, and around 396 nm. According to FIG. 70, in the case ofthe thin film of CP2CPA, absorption was observed at wavelengths ofaround 263 nm, around 298 nm, around 318 nm, around 380 nm, and around402 nm.

According to FIG. 69, the toluene solution of CP2CPA has an emissionpeak at 423 nm (the excitation wavelength: 375 nm). According to FIG.71, the thin film thereof has an emission peak at 444 nm and 540 nm (theexcitation wavelength: 399 nm). Thus, it is found that CP2CPA issuitable for use in a light-emitting element that emits blue light inparticular.

The ionizing potential of the thin film of CP2CPA was measured using aphotoelectron spectrometer (AC-2, manufactured by Riken Keiki Co., Ltd)in the air and found to be 5.67 eV. As a result, the HOMO level wasfound to be −5.67 eV. Further, an absorption edge was obtained from aTauc plot assuming direct transition by use of the data of theabsorption spectrum of CP2CPA in the thin film state, and the absorptionedge was regarded as an optical energy gap. The energy gap was 2.90 eV.A LUMO level of −2.77 eV was obtained from the obtained values of theenergy gap and the HOMO level.

This application is based on Japanese Patent Application serial no.2007-077981 filed on Mar. 23, 2007, filed with Japan Patent Office, theentire contents of which are hereby incorporated by reference.

1. A lighting device comprising a light-emitting element, thelight-emitting element comprising: an anode and a cathode; and a layerinterposed between the anode and the cathode, the layer comprising ananthracene derivative represented by a general formula (1),

wherein Ar represents an aryl group having 6 to 25 carbon atoms, whereinα represents an arylene group having 6 to 25 carbon atoms, wherein A isrepresented by the above structural formula (2-2), wherein β¹ to β³ eachrepresent a substituted or unsubstituted benzene ring, and wherein B isany of hydrogen, an alkyl group having 1 to 4 carbon atoms, an arylgroup having 6 to 25 carbon atoms, a halogen group, and a haloalkylgroup or is represented by the above structural formula (2-2).
 2. Thelighting device according to claim 1, wherein A is represented by astructural formula (3),

wherein, in the structural formula (3), R¹ to R⁶ each represent any ofhydrogen, an alkyl group having 1 to 4 carbon atoms, a halogen group, ahaloalkyl group, and an aryl group having 6 to 25 carbon atoms, whereinB represents any of hydrogen, an alkyl group having 1 to 4 carbon atoms,an aryl group having 6 to 25 carbon atoms, a halogen group, and ahaloalkyl group or is represented by the above structural formula (4),and wherein, in the structural formula (4), R¹ to R⁶ each represent anyof hydrogen, an alkyl group having 1 to 4 carbon atoms, a halogen group,a haloalkyl group, and an aryl group having 6 to 25 carbon atoms.
 3. Thelighting device according to claim 1, wherein A is represented by astructural formula (5), and

wherein B represents any of hydrogen, an alkyl group having 1 to 4carbon atoms, an aryl group having 6 to 25 carbon atoms, a halogengroup, and a haloalkyl group or is represented by the above structuralformula (6).
 4. The lighting device according to claim 1, wherein B ishydrogen.
 5. The lighting device according to claim 1, wherein alight-emitting substance is dispersed in the layer.
 6. The lightingdevice according to claim 1, wherein the layer is in contact with theanode.
 7. The lighting device according to claim 1, wherein the layerfurther comprises an inorganic compound which has an electron acceptingproperty to the anthracene derivative.
 8. The lighting device accordingto claim 7, wherein the inorganic compound is an oxide of Groups 4 to 8metals.
 9. The lighting device according to claim 7, wherein theinorganic compound is selected from vanadium oxide, niobium oxide, andmolybdenum oxide.
 10. A lighting device comprising a light-emittingelement, the light-emitting element comprising: a first electrode; afirst light-emitting unit over the first electrode; a charge generationlayer over the first light-emitting unit; a second light-emitting unitover the charge generation layer; and a second electrode over the secondlight-emitting unit, wherein at least one of the first light-emittingunit and the second light-emitting unit comprises an anthracenederivative represented by a general formula (1),

wherein Ar represents an aryl group having 6 to 25 carbon atoms, whereinα represents an arylene group having 6 to 25 carbon atoms, wherein A isrepresented by the above structural formula (2-2), wherein β¹ to β³ eachrepresent a substituted or unsubstituted benzene ring, and wherein B isany of hydrogen, an alkyl group having 1 to 4 carbon atoms, an arylgroup having 6 to 25 carbon atoms, a halogen group, and a haloalkylgroup or is represented by the above structural formula (2-2).
 11. Thelighting device according to claim 10, wherein A is represented by astructural formula (3),

wherein, in the structural formula (3), R¹ to R⁶ each represent any ofhydrogen, an alkyl group having 1 to 4 carbon atoms, a halogen group, ahaloalkyl group, and an aryl group having 6 to 25 carbon atoms, whereinB represents any of hydrogen, an alkyl group having 1 to 4 carbon atoms,an aryl group having 6 to 25 carbon atoms, a halogen group, and ahaloalkyl group or is represented by the above structural formula (4),and wherein, in the structural formula (4), R¹ to R⁶ each represent anyof hydrogen, an alkyl group having 1 to 4 carbon atoms, a halogen group,a haloalkyl group, and an aryl group having 6 to 25 carbon atoms. 12.The lighting device according to claim 10, wherein A is represented by astructural formula (5), and

wherein B represents any of hydrogen, an alkyl group having 1 to 4carbon atoms, an aryl group having 6 to 25 carbon atoms, a halogengroup, and a haloalkyl group or is represented by the above structuralformula (6).
 13. The lighting device according to claim 10, wherein B ishydrogen.
 14. The lighting device according to claim 10, wherein thecharge generation layer is able to inject an electron to one of thefirst and second light-emitting units and inject a hole to the other ofthe first and second light emitting units.
 15. The lighting deviceaccording to claim 10, wherein the charge generation layer comprises: afirst layer comprising a hole transporting organic compound and a metaloxide; and a second layer comprising an electron transporting organiccompound and an electron-donating material to the electron transportingorganic compound.
 16. A lighting device comprising a light-emittingelement, the light-emitting element comprising: a first electrode; afirst light-emitting layer over the first electrode; a secondlight-emitting layer over the first light-emitting layer; and a secondelectrode over the second light-emitting layer, wherein at least one ofthe first light-emitting layer and the second light-emitting layercomprises an anthracene derivative represented by a general formula (1),

wherein Ar represents an aryl group having 6 to 25 carbon atoms, whereinα represents an arylene group having 6 to 25 carbon atoms, wherein A isrepresented by the above structural formula (2-2), wherein β¹ to β³ eachrepresent a substituted or unsubstituted benzene ring, and wherein B isany of hydrogen, an alkyl group having 1 to 4 carbon atoms, an arylgroup having 6 to 25 carbon atoms, a halogen group, and a haloalkylgroup or is represented by the above structural formula (2-2).
 17. Thelighting device according to claim 16, wherein A is represented by astructural formula (3),

wherein, in the structural formula (3), R¹ to R⁶ each represent any ofhydrogen, an alkyl group having 1 to 4 carbon atoms, a halogen group, ahaloalkyl group, and an aryl group having 6 to 25 carbon atoms, whereinB represents any of hydrogen, an alkyl group having 1 to 4 carbon atoms,an aryl group having 6 to 25 carbon atoms, a halogen group, and ahaloalkyl group or is represented by the above structural formula (4),and wherein, in the structural formula (4), R¹ to R⁶ each represent anyof hydrogen, an alkyl group having 1 to 4 carbon atoms, a halogen group,a haloalkyl group, and an aryl group having 6 to 25 carbon atoms. 18.The lighting device according to claim 16, wherein A is represented by astructural formula (5), and

wherein B represents any of hydrogen, an alkyl group having 1 to 4carbon atoms, an aryl group having 6 to 25 carbon atoms, a halogengroup, and a haloalkyl group or is represented by the above structuralformula (6).
 19. The lighting device according to claim 16, wherein B ishydrogen.
 20. The lighting device according to claim 16, wherein theanthracene derivative is included in one of the first and secondlight-emitting layers.
 21. The lighting device according to claim 16,wherein the anthracene derivative is included in the firstlight-emitting layer.
 22. The lighting device according to claim 16,wherein the anthracene derivative is included in one of the first andsecond light-emitting layers, and wherein the other of the first andsecond light-emitting layers comprises a phosphorescent substance. 23.The lighting device according to claim 16, wherein the anthracenederivative is included in one of the first and second light-emittinglayers, and wherein the other of the first and second light-emittinglayers comprises an electron transporting organic compound.
 24. Thelighting device according to claim 16, further comprising alight-emitting substance in both the first and second light-emittinglayers.